Trigger CI workflows on GitHub Actions by pushing tags

[mkoeppe]

1. If a developers wants to run the standard set of CI tests, just pushing a tag is a simpler interface than creating a pull request: git tag -f "ci" && git push --force github "ci"

2. Also this ensures that releases always trigger a CI test.

Follow-up (wishlist): #29535 Customize CI workflows on GitHub Actions using specially structured tag names

Depends on #29403
Depends on #29341

CC: @dimpase @kliem @orlitzky

Component: porting

Keywords: ci, ContinuousIntegration

Author: Matthias Koeppe

Branch/Commit: 81fa6c3

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/29534

[mkoeppe]

Changed keywords from none to ci, ContinuousIntegration

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Branch: u/mkoeppe/trigger_ci_workflows_on_github_actions_by_pushing_tags

[mkoeppe]

Commit: fd27d88

[mkoeppe]

Last 10 new commits:

fafd554	build/pkgs/libpng/distros/slackware.txt: New
eb9f1c1	build/pkgs/slackware.txt: Add libxml2
f7493d9	build/pkgs/libgd/distros/slackware.txt: Add dependencies
5fe6538	Merge branch 't/29424/slackware__system_packages_fix' into t/29341/optional-test-9.1.rc0
84edb00	.github/workflows/tox-optional.yml: Rename
7b3446f	.github/workflows/tox-optional.yml: Test packages factor 'maximal'
1dda317	Add cmake to packages not tested
bd8a2f9	build/bin/write-dockerfile.sh [fedora]: Use 'yum install -y --download-only' for checking existence of packages
2bbd4b3	Merge branch 't/29341/optional-test-9.1.rc0' into t/29534/trigger_ci_workflows_on_github_actions_by_pushing_tags
fd27d88	Trigger CI with tags

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

81fa6c3

Add documentation

[sagetrac-git]

Changed commit from fd27d88 to 81fa6c3

[mkoeppe]

comment:7

Anyone interested in this?

[dimpase]

comment:8

let me try this.

[dimpase]

comment:9

This is a bit strange. My (shallow) understanding of tags is that they are kind of immutable branches.
Once a commit is tagged, the tag stays there.
Does pushing the same commit (as a part of another branch, say) trigger CI?

[mkoeppe]

comment:10

Yes, the tag doesn't move by itself, but you can move it using git tag -f.

[mkoeppe]

comment:11

The CI workflow is triggered only by pushes to tags, not branches.
Pushing the same tag to the same commit is a no-op and will probably not trigger the workflow.
If you want to restart a check of the same commit, just push a different tag.

[dimpase]

comment:12

This looks and works OK.

[dimpase]

Reviewer: Dima Pasechnik

[mkoeppe]

comment:13

Thanks!

[vbraun]

Changed branch from u/mkoeppe/trigger_ci_workflows_on_github_actions_by_pushing_tags to 81fa6c3