ci: move comment breaking up 'rustflags' for coverage linking

.github/workflows/coverage.yaml

@@ -43,8 +43,13 @@ jobs:
       - name: Install cargo-tarpaulin
         run: cargo install cargo-tarpaulin
 
+      # Note: We manually link zlib. This should be synchronized with the flags set for Linux in .cargo/config.toml.
       - name: Generate coverage report
-        run: cargo tarpaulin --out Html --output-dir coverage
+        run: |
+          cargo tarpaulin \
+            --out Html \
+            --output-dir coverage \
+            --rustflags="-C link-arg=-lz"
 
       - name: Upload coverage to Coveralls
         uses: coverallsapp/github-action@v2