feat(ci): generate rpm changelog from upstream mistral.rs commits

Use actions/rpm-changelog@v1 with repo-url to collect commits from
the upstream mistral.rs repo between release tags and prepend a
changelog entry to the spec file before building the RPM.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/build-release.yml

@@ -87,21 +87,32 @@ jobs:
           name: mistralrs-server-${{ matrix.name }}-fc${{ matrix.fedora_version }}
           path: artifacts/
 
+      - name: Determine version
+        id: version
+        run: |
+          echo "version=${TAG#v}" >> "$GITHUB_OUTPUT"
+        env:
+          TAG: ${{ inputs.tag }}
+
+      - name: Generate changelog
+        uses: https://git.lair.cafe/actions/rpm-changelog@v1
+        with:
+          spec: rpm/mistralrs.spec
+          version: ${{ steps.version.outputs.version }}
+          repo-url: https://github.com/EricLBuehler/mistral.rs.git
+
       - name: Build RPM
         run: |
           rm -f ~/.rpmmacros
-          version="${TAG#v}"
           rpmdev-setuptree
           cp artifacts/mistralrs-server-${{ matrix.name }} ~/rpmbuild/SOURCES/
           cp rpm/systemd/mistralrs@.service ~/rpmbuild/SOURCES/
           cp rpm/systemd/mistralrs@.conf.example ~/rpmbuild/SOURCES/
           rpmbuild -bb rpm/mistralrs.spec \
-            --define "mistralrs_version ${version}" \
+            --define "mistralrs_version ${{ steps.version.outputs.version }}" \
             --define "mistralrs_flavour ${{ matrix.name }}" \
             --undefine dist \
             --define "dist .fc${{ matrix.fedora_version }}"
-        env:
-          TAG: ${{ inputs.tag }}
 
       - name: Upload RPM
         uses: actions/upload-artifact@v3