fix(ci): free disk space before coverage job

- Remove dotnet/android/ghc to free ~10GB disk space
- Exclude verification feature from coverage (tested separately in z3-verification)
- Z3 compilation + LLVM instrumentation together exhaust runner disk

Author: avrabe

.github/workflows/ci.yml

@@ -145,15 +145,23 @@ jobs:
     name: Code Coverage
     runs-on: ubuntu-latest
     steps:
+      - name: Free disk space
+        run: |
+          sudo rm -rf /usr/share/dotnet /usr/local/lib/android /opt/ghc
+          df -h
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: llvm-tools-preview
       - uses: Swatinem/rust-cache@v2
+        with:
+          key: coverage
       - name: Install cargo-llvm-cov
         uses: taiki-e/install-action@cargo-llvm-cov
       - name: Generate coverage
-        run: cargo llvm-cov --all-features --lcov --output-path lcov.info
+        # Exclude verification feature - it's tested separately in z3-verification job
+        # and Z3 compilation + LLVM instrumentation together exhaust disk space
+        run: cargo llvm-cov --lcov --output-path lcov.info
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v4
         with: