Cross build Promtail for ARM with journald support.

[jeschkies]

This is the follow up to #8111 and adds journald support for Promatil
ARM and ARM64 builds.

I've tested it locally with my Raspberry Pi and it works.

Fixes #1459

[grafanabot]

Hello @jeschkies!
Backport pull requests need to be either:

• Pull requests which address bugs,
• Urgent fixes which need product approval, in order to get merged,
• Docs changes.

Please, if the current pull request addresses a bug fix, label it with the type/bug label.
If it already has the product approval, please add the product-approved label. For docs changes, please add the type/docs label.
If none of the above applies, please consider removing the backport label and target the next major/minor release.
Thanks!

[grafanabot]

./tools/diff_coverage.sh ../loki-main/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki

Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell.

+           ingester	0%
+        distributor	0%
+            querier	0%
+ querier/queryrange	0%
+               iter	0%
+            storage	0%
+           chunkenc	0%
+              logql	0%
+               loki	0%

[grafanabot]

./tools/diff_coverage.sh ../loki-main/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki

Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell.

+           ingester	0%
+        distributor	0%
+            querier	0%
+ querier/queryrange	0%
+               iter	0%
+            storage	0%
+           chunkenc	0%
+              logql	0%
+               loki	0%

[grafanabot]

The backport to release-2.7.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new branch
git switch --create backport-8664-to-release-2.7.x origin/release-2.7.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 6099fda48f2f9b347d9c49f6f9fb220054d1de90
# Push it to GitHub
git push --set-upstream origin backport-8664-to-release-2.7.x
git switch main
# Remove the local backport branch
git branch -D backport-8664-to-release-2.7.x

Then, create a pull request where the base branch is release-2.7.x and the compare/head branch is backport-8664-to-release-2.7.x.