Run skopeo via docker in integration test jobs

[pstibrany]

What this PR does

We run integration tests on ubuntu-latest runner, without using build-image. Current ubuntu-latest is ubuntu-22.04, and it has old skopeo version 1.4.1. Even newer (in beta) ubuntu-24.04 still has skopeo version 1.13.3.

Since we need to use skopeo 1.14.2 or later to work with Docker 1.25, we try to run it via docker.

[aknuds1]

Looks like a good fix to me. Oops too fast, it doesn't quite work :D

Doesn't quite work yet.

[duricanikolic]

LGTM

[ying-jeanne]

just noticed latest 2 minor versions are also broken because of skopeo version too old, backport to release 2.12

[grafanabot]

The backport to release-2.12 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-8355-to-release-2.12 origin/release-2.12
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 24ae27e41b91f2091f2f6c11744d407ad80ab663
# Push it to GitHub
git push --set-upstream origin backport-8355-to-release-2.12
git switch main
# Remove the local backport branch
git branch -D backport-8355-to-release-2.12

Then, create a pull request where the base branch is release-2.12 and the compare/head branch is backport-8355-to-release-2.12.

[grafanabot]

The backport to mimir-distributed-release-5.3 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-8355-to-mimir-distributed-release-5.3 origin/mimir-distributed-release-5.3
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 24ae27e41b91f2091f2f6c11744d407ad80ab663
# Push it to GitHub
git push --set-upstream origin backport-8355-to-mimir-distributed-release-5.3
git switch main
# Remove the local backport branch
git branch -D backport-8355-to-mimir-distributed-release-5.3

Then, create a pull request where the base branch is mimir-distributed-release-5.3 and the compare/head branch is backport-8355-to-mimir-distributed-release-5.3.