Remove fuzzit integration

wasmtime is covered by oss-fuzz which should cover large swaths of
cranelift as well, so let's remove that from CI and add it back later if
it's necessary.

cranelift/.github/workflows/main.yml

@@ -25,26 +25,3 @@ jobs:
       run: rustup update stable && rustup default stable
     - run: cargo build
     - run: ci/ensure_deterministic_build.sh
-
-  fuzz:
-    name: Fuzz Regression
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v1
-    - name: Install Rust
-      run: rustup update nightly && rustup default nightly
-    - run: cargo install cargo-fuzz
-    - run: ci/fuzzit.sh local-regression
-
-  fuzz_push:
-    name: Fuzz (push)
-    runs-on: ubuntu-latest
-    if: github.event_name == 'push'
-    steps:
-    - uses: actions/checkout@v1
-    - name: Install Rust
-      run: rustup update nightly && rustup default nightly
-    - run: cargo install cargo-fuzz
-    - run: ci/fuzzit.sh fuzzing
-      env:
-        FUZZIT_API_KEY: ${{ secrets.FUZZIT_API_KEY }}