feat(actions): update actionslib, support self:, misc fixes (#39358)

Updates actionslib to https://gitea.com/gitea/actionslib/releases/tag/v1.2.1, moves workflow
parsing into it and aligns behaviour with GitHub.

1. `uses:` supports `self:` (Gitea-only feature) and `$/` paths.
1. `strategy`, `matrix`, `max-parallel` and `fail-fast` accept
expressions, including over `needs`. A job whose `name`, `runs-on` or
`continue-on-error` reads `needs` is resolved once they finish.
1. A job `if:` may only read `github`, `needs`, `vars` and `inputs` and
is decided before the matrix, as on github.com.
1. Matrix `fail-fast` cancels the other combinations, and `always()`
jobs keep running when a run is cancelled.
1. Invalid workflow files, including a malformed `on:` and unknown or
cyclic `needs`, show up on push as failed runs with the error.
1. A job whose `if:` or `concurrency:` fails to evaluate is skipped or
failed with the error, instead of staying blocked.
1. Reusable workflows: a missing and an unreadable repository fail
alike, public callers cannot use private workflows, nested jobs cannot
exceed the caller's token permissions.
1. Runner labels match case-insensitively, and `runs-on` accepts an
array from an expression.

Runner PR: https://gitea.com/gitea/runner/pulls/1247
Docs PR: https://gitea.com/gitea/docs/pulls/553
Fixes: https://github.com/go-gitea/gitea/issues/38990
Fixes: https://github.com/go-gitea/gitea/issues/39382
Fixes: https://github.com/go-gitea/gitea/issues/32364
Fixes: https://github.com/go-gitea/gitea/issues/36077
Fixes: https://github.com/go-gitea/gitea/issues/23277
Fixes: https://github.com/go-gitea/gitea/issues/29020
Co-authored-by: Claude (Opus 5) <noreply@anthropic.com>
Co-authored-by: Zettat123 <zettat123@gmail.com>

modules/actions/jobparser/testdata/multiple_matrix.out.yaml

@@ -14,6 +14,8 @@ jobs:
           - ubuntu-20.04
         version:
           - 1.17
+      job-index: 3
+      job-total: 6
 ---
 name: test
 jobs:
@@ -31,6 +33,8 @@ jobs:
           - ubuntu-20.04
         version:
           - 1.18
+      job-index: 4
+      job-total: 6
 ---
 name: test
 jobs:
@@ -48,6 +52,8 @@ jobs:
           - ubuntu-20.04
         version:
           - 1.19
+      job-index: 5
+      job-total: 6
 ---
 name: test
 jobs:
@@ -65,6 +71,7 @@ jobs:
           - ubuntu-22.04
         version:
           - 1.17
+      job-total: 6
 ---
 name: test
 jobs:
@@ -82,6 +89,8 @@ jobs:
           - ubuntu-22.04
         version:
           - 1.18
+      job-index: 1
+      job-total: 6
 ---
 name: test
 jobs:
@@ -99,3 +108,5 @@ jobs:
           - ubuntu-22.04
         version:
           - 1.19
+      job-index: 2
+      job-total: 6