Potential fix for code scanning alert no. 3: Workflow does not contain permissions (#439)

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: thpierce

.github/workflows/pr-build.yml

@@ -7,6 +7,8 @@ on:
 jobs:
   build:
     name: Build Java ${{ matrix.java }} on ${{ matrix.os }}
+    permissions:
+      contents: read
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false