feat: mark skipped checks as skipped (#12606)

A separate commit status is introduced for skipped checks. That enables marking them as such in the UI instead of successful, which could be misleading.

Resolves https://codeberg.org/forgejo/forgejo/issues/10138.

## Checklist

The [contributor guide](https://forgejo.org/docs/next/contributor/) contains information that will be helpful to first time contributors. All work and communication must conform to Forgejo's [AI Agreement](https://codeberg.org/forgejo/governance/src/branch/main/AIAgreement.md). 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 for Go changes

(can be removed for JavaScript changes)

- I added test coverage for Go changes...
  - [x] in their respective `*_test.go` for unit tests.
  - [x] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I ran...
  - [x] `make pr-go` before pushing

### Tests for JavaScript changes

(can be removed for Go changes)

- 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)).

### Documentation

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

### Release notes

- [x] This change will be noticed by a Forgejo user or admin (feature, bug fix, performance, etc.). I suggest to include a release note for this change.
- [ ] This change is not visible to a Forgejo user or admin (refactor, dependency upgrade, etc.). I think there is no need to add a release note for this change.

*The decision if the pull request will be shown in the release notes is up to the mergers / release team.*

The content of the `release-notes/<pull request number>.md` file will serve as the basis for the release notes. If the file does not exist, the title of the pull request will be used instead.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12606
Reviewed-by: Cyborus <cyborus@disroot.org>
Reviewed-by: Mathieu Fenniak <mfenniak@noreply.codeberg.org>

templates/repo/commit_status.tmpl

@@ -5,6 +5,9 @@
 {{if eq .State "success"}}
 	{{svg "octicon-check" 18 "commit-status icon text green"}}
 {{end}}
+{{if eq .State "skipped"}}
+	{{svg "octicon-skip" 18 "commit-status icon text grey"}}
+{{end}}
 {{if eq .State "error"}}
 	{{svg "gitea-exclamation" 18 "commit-status icon text red"}}
 {{end}}

templates/repo/pulls/status.tmpl

@@ -14,6 +14,8 @@ Template Attributes:
 			{{ctx.Locale.Tr "repo.pulls.status_checking"}}
 		{{else if eq .CommitStatus.State "success"}}
 			{{ctx.Locale.Tr "repo.pulls.status_checks_success"}}
+		{{else if eq .CommitStatus.State "skipped"}}
+			{{ctx.Locale.Tr "repo.pulls.status_checks_skipped"}}
 		{{else if eq .CommitStatus.State "warning"}}
 			{{ctx.Locale.Tr "repo.pulls.status_checks_warning"}}
 		{{else if eq .CommitStatus.State "failure"}}

templates/swagger/v1_json.tmpl

@@ -24114,7 +24114,7 @@
       "x-go-package": "forgejo.org/modules/structs"
     },
     "CommitStatusState": {
-      "description": "CommitStatusState holds the state of a CommitStatus\nIt can be \"pending\", \"success\", \"error\", \"failure\" and \"warning\"",
+      "description": "CommitStatusState holds the state of a CommitStatus\nIt can be \"pending\", \"success\", \"error\", \"failure\", \"warning\", or \"skipped\"",
       "type": "string",
       "x-go-package": "forgejo.org/modules/structs"
     },