GitHub: only run cover on some itests, send completion

We only want to run the coverage on some select tests, since we don't
want to make tests with slow backends even slower.
And because we use "parallel: true" when uploading the coverage results,
those will only be assembled once we send "parallel-finished: true"
using the goveralls action.
So we do that with a new "finish" job.

.github/workflows/main.yml

@@ -241,13 +241,13 @@ jobs:
       matrix:
         include:
           - name: btcd
-            args: backend=btcd
+            args: backend=btcd cover=1
           - name: bitcoind
-            args: backend=bitcoind
+            args: backend=bitcoind cover=1
           - name: bitcoind-notxindex
             args: backend="bitcoind notxindex"
           - name: bitcoind-rpcpolling
-            args: backend="bitcoind rpcpolling"
+            args: backend="bitcoind rpcpolling" cover=1
           - name: bitcoind-etcd
             args: backend=bitcoind dbbackend=etcd
           - name: bitcoind-postgres
@@ -259,7 +259,7 @@ jobs:
           - name: bitcoind-sqlite-nativesql
             args: backend=bitcoind dbbackend=sqlite nativesql=true
           - name: neutrino
-            args: backend=neutrino
+            args: backend=neutrino cover=1
     steps:
       - name: git checkout
         uses: actions/checkout@v3
@@ -274,9 +274,10 @@ jobs:
         run: ./scripts/install_bitcoind.sh $BITCOIN_VERSION
 
       - name: run ${{ matrix.name }}
-        run: make itest-parallel ${{ matrix.args }} cover=1
+        run: make itest-parallel ${{ matrix.args }}
 
       - name: Send coverage
+        if: ${{ contains(matrix.args, 'cover=1') }}
         uses: shogo82148/actions-goveralls@v1
         with:
           path-to-profile: coverage.txt
@@ -407,3 +408,13 @@ jobs:
 
       - name: release notes check
         run: scripts/check-release-notes.sh
+  
+  # Notify about the completion of all coverage collecting jobs.
+  finish:
+    if: ${{ always() }}
+    needs: [unit-test, ubuntu-integration-test]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: shogo82148/actions-goveralls@v1
+        with:
+          parallel-finished: true