Restore coverage (#2684)

* Update coverage workflow

* Remove cache layer, up timeout to 60 minutes anyway

.github/workflows/coverage.yml

@@ -14,7 +14,7 @@ jobs:
   coverage:
     name: Coverage (+nightly)
     # The large timeout is to accommodate nightly builds
-    timeout-minutes: 45
+    timeout-minutes: 60
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2.3.4
@@ -28,15 +28,8 @@ jobs:
           profile: minimal
           components: llvm-tools-preview
 
-      - uses: Swatinem/rust-cache@v1
-
-      - name: Install rustfilt symbol demangler
-        run: |
-          cargo install rustfilt
-
       - name: Install cargo-llvm-cov cargo command
-        run: |
-          cargo install cargo-llvm-cov --version ^0.1.0-alpha.4
+        run: cargo install cargo-llvm-cov
 
       - name: Generate code coverage
         env:
@@ -45,4 +38,4 @@ jobs:
         run: cargo llvm-cov --lcov > lcov.info
 
       - name: Upload coverage report to Codecov
-        uses: codecov/codecov-action@v1.5.2
+        uses: codecov/codecov-action@v2.0.3