ci(aur): publish the AUR packages from CI

A release tag now updates and pushes all three AUR packages once the
GitHub release exists, then commits the refreshed recipes back to main.
A push to main that changes the -git recipe publishes that package
alone; plain upstream commits need no AUR push because its pkgver()
follows git at build time.

Needs the AUR_SSH_PRIVATE_KEY repository secret.

.github/workflows/release.yml

@@ -202,3 +202,13 @@ jobs:
           prerelease: false
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  aur:
+    name: Publish AUR packages
+    needs: build-release
+    if: startsWith(github.ref, 'refs/tags/')
+    uses: ./.github/workflows/aur.yml
+    with:
+      version: ${{ github.ref_name }}
+    secrets:
+      AUR_SSH_PRIVATE_KEY: ${{ secrets.AUR_SSH_PRIVATE_KEY }}