Fix: disable building postfix-expoter for ppc64le and s390x

Builds fail:

```
[linux/s390x builder 8/8] RUN env GOOS="linux" GOARCH="s390x" GOARM="$( echo "" | grep -E -o "\d+$")" go build -ldflags '-extldflags "-static"'  -o /bin/postfix_exporter
606.1 net: gcc: signal: segmentation fault (core dumped)
...
```

```
[linux/ppc64le builder 8/8] RUN env GOOS="linux" GOARCH="ppc64le" GOARM="$( echo "" | grep -E -o "\d+$")" go build -ldflags '-extldflags "-static"'  -o /bin/postfix_exporter
ERROR: process "/bin/sh -c env GOOS=\"${TARGETOS}\" GOARCH=\"${TARGETARCH}\" GOARM=\"$( echo \"$TARGETVARIANT\" | grep -E -o \"\\\\d+$\")\" go build -ldflags '-extldflags \"-static\"'  -o /bin/postfix_exporter" did not complete successfully: exit code: 1
gcc: internal compiler error: Segmentation fault signal terminated program cc1
Please submit a full bug report, with preprocessed source (by using -freport-bug).
See <file:///usr/share/doc/gcc-12/README.Bugs> for instructions.
```

.github/actions/build-postfix-exporter/action.yaml

@@ -19,9 +19,9 @@ runs:
     - name: Checkout
       uses: actions/checkout@v4
       with:
-        repository: Hsn723/postfix_exporter # Hsn723 repo is actually being updated
+        repository: kumina/postfix_exporter
         path: 'postfix_exporter'
-        ref: 'v0.7.0' # Latest commit we know that works
+        ref: 'a6f58e9b2b2b4decc7e65c5a34b4fd53cd6665f1' # Latest commit we know that works
 
     - name: Apply patches
       shell: bash
@@ -68,8 +68,8 @@ runs:
         push: true
         tags: '${{ inputs.tags }}'
         labels: ${{ steps.meta.outputs.labels }}
-        platforms: "linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/mips64le,linux/ppc64le,linux/s390x"
+        platforms: "linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le"
-        # linux/386,linux/arm/v6,linux/arm64,linux/riscv64"
+        #platforms: "linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,linux/ppc64le,linux/s390x"
         cache-from: type=local,src=/tmp/.buildx-cache/postfix-exporter,mode=max,compression=estargz
         cache-to: type=local,dest=/tmp/.buildx-cache-new/postfix-exporter
 

Dockerfile

@@ -7,7 +7,7 @@
 #
 # - use Alpine if you're strapped for space. But beware it uses MUSL LIBC, so unicode support might be an issue.
 # - use Debian if you're interested in the greatest cross-platform compatibility. It is larger than Alpine, though.
-# - use Ubuntu if, well, Ubuntu is your thing and you're used to Ubuntu ecosystem.
+# - use Ubuntu if, well, Ubuntu is your thing and you're used to the buntu ecosystem.
 ARG BASE_IMAGE=debian:bookworm-slim
 
 FROM ${BASE_IMAGE} AS build-scripts
@@ -32,7 +32,7 @@ FROM base AS sasl
 
 ARG TARGETPLATFORM
 ARG SASL_XOAUTH2_REPO_URL=https://github.com/tarickb/sasl-xoauth2.git
-ARG SASL_XOAUTH2_GIT_REF=release-0.26
+ARG SASL_XOAUTH2_GIT_REF=release-0.25
 
 #           --mount=type=cache,target=/var/cache/apk,sharing=locked,id=var-cache-apk-$TARGETPLATFORM \
 #           --mount=type=cache,target=/etc/apk/cache,sharing=locked,id=etc-apk-cache-$TARGETPLATFORM \

README.md

@@ -131,7 +131,7 @@ Several potentially "surprising" changes went into this issue and hence warrant
 - **[`master`](https://github.com/bokysan/docker-postfix/tree/master/) branch now builds images called [`edge`](https://hub.docker.com/r/boky/postfix/tags?page=1&name=edge)**. 
   `latest` images are built from the last tag. We've had several issues with people using the `latest` tag
   and reporting problems. You can now rely on `latest` being the latest stable release.
-- Image now builds its own version of [postfix-exporter](https://github.com/hsn723/postfix_exporter) and relies on this
+- Image now builds its own version of [postfix-exporter](https://github.com/kumina/postfix_exporter) and relies on this
   third-party project. Checkout is from master branch, based
   on specific SHA commit id. The same hash is used for master and tags.
 - **Architecture galore!** With the addition of debian images, we now support support more architectures than ever. The list includes: 

postfix-exporter-01.patch

@@ -1,34 +1,25 @@
 diff --git a/Dockerfile b/Dockerfile
-index 75a22d8..81145c9 100644
+index a3327d8..1cdfa84 100644
 --- a/Dockerfile
 +++ b/Dockerfile
-@@ -1,8 +1,41 @@
+@@ -1,4 +1,10 @@
--FROM scratch
+-FROM golang:1.16 AS builder
 +# syntax=docker/dockerfile:1.2
-+FROM golang:1.23 AS builder
++FROM golang:1.21.3-bookworm AS builder
- LABEL org.opencontainers.image.source="https://github.com/hsn723/postfix_exporter" \
-         org.opencontainers.image.authors="Hsn723" \
-         org.opencontainers.image.title="postfix_exporter"
 +ARG TARGETPLATFORM
 +ARG TARGETOS
 +ARG TARGETARCH
 +ARG TARGETVARIANT
 +
-+WORKDIR /src
+ WORKDIR /src
-+
+ 
-+# avoid downloading the dependencies on successive builds
+ # avoid downloading the dependencies on succesive builds
-+RUN apt-get update -qq && apt-get install -qqy \
+@@ -14,10 +20,18 @@ COPY . .
-+  build-essential \
+ 
-+  libsystemd-dev
+ # Force the go compiler to use modules
-+
+ ENV GO111MODULE=on
-+COPY go.mod go.sum ./
+-RUN go test
-+RUN go mod download
+-RUN go build -o /bin/postfix_exporter
-+RUN go mod verify
-+
-+COPY . .
-+
-+# Force the go compiler to use modules
-+ENV GO111MODULE=on
 +# go test fails (sometimes) because it relies on an external dependency:
 +#
 +# warning: SASL authentication failure: cannot connect to saslauthd server: Permission denied
@@ -39,12 +30,10 @@ index 75a22d8..81145c9 100644
 +# Hence disabling the test here.
 +# RUN go test
 +RUN env GOOS="${TARGETOS}" GOARCH="${TARGETARCH}" GOARM="$( echo "$TARGETVARIANT" | grep -E -o "\\d+$")" go build -ldflags '-extldflags "-static"'  -o /bin/postfix_exporter
-+
+ 
+-FROM debian:latest
 +FROM scratch
  EXPOSE 9154
--COPY postfix_exporter /
+ WORKDIR /
--COPY LICENSE /
+ COPY --from=builder /bin/postfix_exporter /bin/
--ENTRYPOINT ["/postfix_exporter"]
+ 
-+WORKDIR /
-+COPY --from=builder /bin/postfix_exporter /bin/
-+ENTRYPOINT ["/bin/postfix_exporter"]