feat: support workflow inputs on expanded reusable workflows (#10614)

Follow-up to #10525; adds support for `on.workflow_call.inputs` to expanded reusable workflows (when no `runs-on` is specified in a job that `uses: ...` another workflow).

The majority of the work for this is done by the `jobparser` library which evaluates inputs automatically when the job is being parsed and stores those inputs on the expanded jobs as the "default" value in `on.workflow_call.inputs`.  Forgejo's role here is just to to ensure that `forgejo.event_name` is set to `"workflow_call"` when a job is dispatched, which causes the runner to use the inputs that are stored -- 34c20aa50f/act/runner/expression.go (L452-L467).

## Checklist

The [contributor guide](https://forgejo.org/docs/next/contributor/) contains information that will be helpful to first time contributors. There also are a few [conditions for merging Pull Requests in Forgejo repositories](https://codeberg.org/forgejo/governance/src/branch/main/PullRequestsAgreement.md). You are also welcome to join the [Forgejo development chatroom](https://matrix.to/#/#forgejo-development:matrix.org).

### Tests

- I added test coverage for Go changes...
  - [x] in their respective `*_test.go` for unit tests.
  - [ ] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I added test coverage for JavaScript changes...
  - [ ] in `web_src/js/*.test.js` if it can be unit tested.
  - [ ] in `tests/e2e/*.test.e2e.js` if it requires interactions with a live Forgejo server (see also the [developer guide for JavaScript testing](https://codeberg.org/forgejo/forgejo/src/branch/forgejo/tests/e2e/README.md#end-to-end-tests)).
- **end-to-end testing**: https://code.forgejo.org/forgejo/end-to-end/pulls/1323

### Documentation

- [x] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
    - https://codeberg.org/forgejo/docs/pulls/1664
- [ ] I did not document these changes and I do not expect someone else to do it.

### Release notes

- [ ] I do not want this change to show in the release notes.
- [x] I want the title to show in the release notes with a link to this pull request.
- [ ] I want the content of the `release-notes/<pull request number>.md` to be be used for the release notes instead of the title.

<!--start release-notes-assistant-->

## Release notes
<!--URL:https://codeberg.org/forgejo/forgejo-->
- Features
  - [PR](https://codeberg.org/forgejo/forgejo/pulls/10614): <!--number 10614 --><!--line 0 --><!--description c3VwcG9ydCB3b3JrZmxvdyBpbnB1dHMgb24gZXhwYW5kZWQgcmV1c2FibGUgd29ya2Zsb3dz-->support workflow inputs on expanded reusable workflows<!--description-->
<!--end release-notes-assistant-->

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/10614
Reviewed-by: Andreas Ahlenstorf <aahlenst@noreply.codeberg.org>
Co-authored-by: Mathieu Fenniak <mathieu@fenniak.net>
Co-committed-by: Mathieu Fenniak <mathieu@fenniak.net>

services/actions/task.go

@@ -88,7 +88,10 @@ func generateTaskContext(t *actions_model.ActionTask) (*structpb.Struct, error)
 		return nil, err
 	}
 
-	gitCtx := GenerateGiteaContext(t.Job.Run, t.Job)
+	gitCtx, err := GenerateGiteaContext(t.Job.Run, t.Job)
+	if err != nil {
+		return nil, err
+	}
 	gitCtx["token"] = t.Token
 	gitCtx["gitea_runtime_token"] = giteaRuntimeToken