feat(workflow): Added notify-plugin-authors for issues

[spiros132]

Workflow

Added a workflow so that all issues that have to do with plugins will be CC with the appropriate author.

This should make it less manual for the maintainers so that they don't have to check each issue manually, and also so that each author gets notified when an issue is opened about their plugin.

[ItsLemmy]

1. non-blocking - .github/workflows/issues-notify-plugin-authors.py:33
   Expected user input errors exit non-zero, so the workflow run goes red instead of
   quietly no-opping. Replaying the parser over all 21 existing repository issues,
   4 would exit 1: [BUG] <Audio Switcher> Mute/Unmute button remain unchange when press to switch #117 ("Audio Switcher"), [BUG] Keymap plugin incompatiable #113
   ("https://noctalia.dev/plugins/community/keymap"), [BUG] keybind-cheatsheet Parse Error at line 15 #111 ("keybind-cheatsheet"),
   Game Launcher does not detect Steam games on NixOS #73 ("game-launcher"). The Plugin field is free text, so roughly one in five
   real issues produces a failed Actions run and a maintainer notification with no
   comment posted. Same applies to .github/workflows/issues-notify-plugin-authors.py:46.
   Exiting 0 on unparseable input keeps the notifier best effort. Two of those four
   cases ([BUG] keybind-cheatsheet Parse Error at line 15 #111, Game Launcher does not detect Steam games on NixOS #73) are already valid directory names, so falling back to treating a
   single-segment value as the directory would also recover them.

2. non-blocking - .github/workflows/issues-notify-plugin-authors.py:43
   author = repo.get_commits(path=...).reversed[0].author.login dereferences a field
   the GitHub API sets to null when the commit email is not linked to an account.
   PyGithub returns None there rather than an empty object (github/Commit.py author
   property plus _makeClassAttribute null branch), so .login raises AttributeError and
   the run fails before reaching the guard at
   .github/workflows/issues-notify-plugin-authors.py:50, which is therefore unreachable.
   Checking every current plugin, all 51 first-manifest commits resolve to a real login,
   so this is latent rather than observed.

3. non-blocking - .github/workflows/issues-notify-plugin-authors.py:43
   Author resolution uses the first commit that touched

   /plugin.toml. This is the
   right call over the id author segment, which is frequently not a GitHub login
   (tadomika_ari vs Tadomika-Ari, lux vs luxqw, kenn vs cheerfulScumbag, neuro vs
   13ghosts, alexander vs Ahmed5Emad), and history currently contains no plugin
   directory renames. Two consequences worth knowing: get_commits(path=) does not
   follow renames, and the original submitter is CC'd even if a plugin later changes
   hands.

4. non-blocking - .github/workflows/issues-notify-plugin-authors.yml:11
   No repository guard, unlike .github/workflows/update-catalog.yml:20
   (if: github.repository == 'noctalia-dev/community-plugins'). Any fork with issues
   enabled will run this and comment on its own issues. Also
   .github/workflows/issues-notify-plugin-authors.yml:18 passes python-version: 3.14
   unquoted, which YAML parses as a float; it happens to stringify correctly here, but
   quoting it avoids the 3.10 to 3.1 class of breakage on future bumps.

5. non-blocking - .github/workflows/issues-notify-plugin-authors.yml:21
   pip install PyGithub adds the repository's only third-party CI dependency, unpinned,
   into a job holding an issues: write token. The script uses three API calls
   (get issue, list commits for a path, create comment), all reachable with stdlib
   urllib or actions/github-script, so the dependency is avoidable. If it stays, pin the
   version.

6. non-blocking - .github/workflows/issues-notify-plugin-authors.py:22
   issue.body is used without a None check and lines.index("### Plugin") raises
   ValueError when the heading is absent. Blank issues are disabled
   (.github/ISSUE_TEMPLATE/config.yml:1) and both forms make Plugin required, so this
   only bites on API-created, imported, or transferred issues, where it surfaces as a
   raw traceback. The scan loop at
   .github/workflows/issues-notify-plugin-authors.py:26 also leaves i unbound if the
   heading is the final line.

[ItsLemmy]

Thanks!