ci: download Gitea tool binaries

.gitea/workflows/fuzz.yml

@@ -16,6 +16,7 @@ env:
   CARGO_TERM_COLOR: always
   # Pinned for reproducibility; bump deliberately alongside `fuzz/Cargo.lock`.
   CARGO_FUZZ_VERSION: 0.13.1
+  CARGO_FUZZ_SHA256: 86edc9b8f20c29ff07c3e5fcd67bc3f0784b3b960a5428635060f20d50555461
 
 jobs:
   fuzz-smoke:
@@ -44,7 +45,16 @@ jobs:
         run: rustup toolchain install nightly --profile minimal --no-self-update
 
       - name: Install cargo-fuzz
-        run: cargo install cargo-fuzz --locked --version "${CARGO_FUZZ_VERSION}"
+        run: |
+          set -euo pipefail
+          archive="cargo-fuzz-${CARGO_FUZZ_VERSION}-x86_64-unknown-linux-musl.tar.gz"
+          curl --fail --show-error --location --retry 3 \
+            "https://github.com/rust-fuzz/cargo-fuzz/releases/download/${CARGO_FUZZ_VERSION}/${archive}" \
+            --output "$archive"
+          echo "${CARGO_FUZZ_SHA256}  ${archive}" | sha256sum --check --status -
+          tar -xzf "$archive" cargo-fuzz
+          install -Dm755 cargo-fuzz "${RUNNER_TEMP}/bin/cargo-fuzz"
+          echo "${RUNNER_TEMP}/bin" >> "$GITHUB_PATH"
 
       - name: Build all fuzz targets
         run: cargo +nightly fuzz build