Run CI's checks, the server tests and the other Go tests as three parallel jobs, without coverage

The server package's race run takes about as long as all other packages together, so it gets its own job. Coverage was only printed to the log, and its instrumentation slowed the race run.

.github/workflows/test.yaml

@@ -5,7 +5,12 @@ on:
   pull_request:
 jobs:
   test:
+    name: test (${{ matrix.part }})
     runs-on: ubuntu-24.04
+    strategy:
+      fail-fast: false
+      matrix:
+        part: [checks, server, rest] # In parallel: the server package takes as long as all others together
     services:
       postgres:
         image: postgres:17
@@ -44,6 +49,11 @@ jobs:
       - name: Build web app (required for tests)
         run: make web
       - name: Run web tests, formatting, vetting and linting
-        run: make web-test web-fmt-check fmt-check vet web-lint lint staticcheck template-check go-check # The Go tests run once, with -race, in coverage
-      - name: Run Go tests (race detector, coverage)
-        run: make coverage
+        if: matrix.part == 'checks'
+        run: make web-test web-fmt-check fmt-check vet web-lint lint staticcheck template-check go-check
+      - name: Run Go tests of the server package (race detector)
+        if: matrix.part == 'server'
+        run: go test -race ./server
+      - name: Run Go tests of all other packages (race detector)
+        if: matrix.part == 'rest'
+        run: go test -race $(go list -f '{{if or .TestGoFiles .XTestGoFiles}}{{.ImportPath}}{{end}}' ./... | grep -vE 'ntfy/v2/(test|examples|tools|web|server)$')