ci(gitea): Add gitea runner

May not work, Testing this runner..

.gitea/workflows/build.yaml

@@ -0,0 +1,14 @@
+name: Run Build
+run-name: ${{ gitea.actor }} building code
+on: push
+
+jobs:
+  dotnet:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - uses: actions/setup-dotnet@v5
+        with:
+          dotnet-version: 10.x
+          cache: true
+      - run: dotnet build cssitegen