added code coverage in CI

.github/workflows/rust.yml

@@ -11,6 +11,8 @@ on:
     secrets:
       NPCAP_OEM_URL:
         required: true
+      CODECOV_TOKEN:
+        required: true
 
 env:
   CARGO_TERM_COLOR: always
@@ -50,12 +52,31 @@ jobs:
 
       - name: fmt
         run: cargo fmt --all -- --check
+
       - name: build
         if: matrix.os != 'windows' || github.event_name != 'pull_request'
         run: cargo build --verbose
+
       - name: clippy
         if:  matrix.os != 'windows' || github.event_name != 'pull_request'
         run: cargo clippy -- -D warnings
+
       - name: test
         if: matrix.os != 'windows' || github.event_name != 'pull_request'
         run: cargo test --verbose -- --nocapture
+
+      - name: Install cargo-llvm-cov
+        if: matrix.os == 'ubuntu'
+        uses: taiki-e/install-action@cargo-llvm-cov
+
+      - name: Generate code coverage
+        if: matrix.os == 'ubuntu'
+        run: cargo llvm-cov --all-features --workspace --lcov --output-path lcov.info
+
+      - name: Upload coverage to Codecov
+        if: matrix.os == 'ubuntu'
+        uses: codecov/codecov-action@v4
+        with:
+          files: lcov.info
+          fail_ci_if_error: false
+          token: ${{ secrets.CODECOV_TOKEN }}