Sequence windows after build job to avoid CI runner contention

Both jobs land on the same self-hosted runner. Run 129 segfaulted
odin test in build while windows was mid (uncached) SDK download/
splat at the same time; odin check passed and the test suite
reproduces fine in isolation, so this is resource contention from
running concurrently for the first time, not a code or toolchain bug.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitea/workflows/gitea-build.yaml

@@ -33,8 +33,15 @@ jobs:
       - name: Build
         run: just release
 
-  # Cross-compiles for Windows so link breakages show up before a release
+  # Cross-compiles for Windows so link breakages show up before a release.
+  # Runs after `build`: both jobs land on the same self-hosted runner, and the
+  # first run segfaulted `odin test` in `build` while `windows` was doing its
+  # (uncached) SDK download/splat at the same time - resource contention, not
+  # a code or toolchain bug (odin check passed; the test suite reproduces fine
+  # in isolation). Sequencing avoids that contention at the cost of a longer
+  # total run.
   windows:
+    needs: build
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Repository