upload_test_binaries clears testsuite before downloading artifact

The previous state was that the build_assemblyscript, build_c, and
build_rust workflows upload tests/*/testsuite as an artifact, and then
upload_test_binaries runs once for each of {rust,assemblyscript,c},
removing any wasm file in tests/*lang*/testsuite, downloading the
artifact, unpacking it to tests/*lang*/testsuite, and adding and
committing to prod/testsuite/base if any file differed.

This PR implements a more simple and robust approach, which is to just
have upload_test_binaries remove tests/*lang*/testsuite before unpacking
the artifact.

Author: wingo

.github/workflows/compile-tests.yml

@@ -153,7 +153,7 @@ jobs:
         run: git merge ${{ github.sha }}
 
       - name: Remove existing binaries
-        run: git rm --ignore-unmatch tests/${{ matrix.suite }}/testsuite/*.wasm
+        run: rm -rf tests/${{ matrix.suite }}/testsuite
 
       - name: Download ${{ matrix.suite }} test binaries
         uses: actions/download-artifact@v4
@@ -164,6 +164,6 @@ jobs:
       - name: Publish changes to consumer branch
         shell: bash
         run: |
-          git add tests/${{ matrix.suite }}/testsuite/*.wasm -f
-          git diff --quiet --cached || git commit -m "Update test binaries for ${{ matrix.suite }} test suite"
+          git add -f tests/${{ matrix.suite }}/testsuite
+          git diff --quiet || git commit -m "Update test binaries for ${{ matrix.suite }} test suite"
           git push