Remove build.sh step from 'source-root' test

As this test is using only JS, it's not necessary to compile or analyze the other languages.

.github/workflows/pr-checks.yml

@@ -905,9 +905,6 @@ jobs:
       with:
         languages: javascript
         source-root: tests/multi-language-repo
-    - name: Build code
-      shell: bash
-      run: ./build.sh
     - uses: ./analyze
       with:
         output: "${{ runner.temp }}/results"