CI: optimize builds to run short jobs with less concurrency

.github/workflows/main.yml

@@ -104,35 +104,18 @@ jobs:
         with:
           name: distribution
           path: distribution
-  Linux32:
-    runs-on: ubuntu-latest
-    needs: Prebuild
-    steps:
-      - uses: actions/checkout@v3
-      - name: 'Linux 32-bit'
-        run: build-scripts/build-linux32
   pikepdf:
+    strategy:
+      fail-fast: false
+      max-parallel: 1
+      matrix:
+        future: ['', 'future']
     runs-on: ubuntu-latest
     needs: Prebuild
     steps:
       - uses: actions/checkout@v3
       - name: 'pikepdf'
-        run: build-scripts/test-pikepdf
-  pikepdf-future:
-    runs-on: ubuntu-latest
-    # Run after pikepdf to save concurrent runners
-    needs: pikepdf
-    steps:
-      - uses: actions/checkout@v3
-      - name: 'qpdf + pikepdf with FUTURE'
-        run: build-scripts/test-pikepdf future
-  Fuzzers:
-    runs-on: ubuntu-latest
-    needs: Prebuild
-    steps:
-      - uses: actions/checkout@v3
-      - name: 'Build Fuzzer'
-        run: build-scripts/build-fuzzer
+        run: build-scripts/test-pikepdf ${{ matrix.future }}
   Sanitizers:
     runs-on: ubuntu-latest
     needs: Prebuild
@@ -140,18 +123,19 @@ jobs:
       - uses: actions/checkout@v3
       - name: 'Sanitizer Tests'
         run: build-scripts/test-sanitizers
-  UnsignedChar:
+  QuickJobs:
     runs-on: ubuntu-latest
     needs: Prebuild
+    strategy:
+      fail-fast: false
+      max-parallel: 3
+      matrix:
+        script:
+          - build-fuzzer
+          - build-linux32
+          - test-unsigned-char
+          - test-c++-next
     steps:
       - uses: actions/checkout@v3
-      - name: 'Unsigned Char Tests'
-        run: build-scripts/test-unsigned-char
-  CxxNext:
-    runs-on: ubuntu-latest
-    # Build after Fuzzers to save concurrent runners
-    needs: Fuzzers
-    steps:
-      - uses: actions/checkout@v3
-      - name: 'Build with Next C++ standard'
-        run: build-scripts/test-c++-next
+      - name: ${{ matrix.script }}
+        run: build-scripts/${{ matrix.script }}