persist fuzz corpus between CI runs

Author: Anyitechs

.github/workflows/build.yml

@@ -267,6 +267,16 @@ jobs:
       - name: Install Rust ${{ env.TOOLCHAIN }} toolchain
         run: |
           curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --profile=minimal --default-toolchain ${{ env.TOOLCHAIN }}
+      - name: Restore/Save persistent honggfuzz corpus
+        uses: actions/cache@v4
+        with:
+          path: fuzz/hfuzz_workspace
+          key: fuzz-corpus-${{ github.ref }}-${{ github.sha }}
+          restore-keys: |
+            # First, try to restore the latest cache from this PR
+            fuzz-corpus-${{ github.ref }}-
+            # If it's a new PR (or not a PR), restore the latest from main
+            fuzz-corpus-refs/heads/main-
       - name: Sanity check fuzz targets on Rust ${{ env.TOOLCHAIN }}
         run: |
           cd fuzz