Try pinning lcov to v2.0

For compatabilty with Ubuntu.

.github/workflows/build.yaml

@@ -7,6 +7,7 @@ permissions:
 
 jobs:
   linux:
+    if: false
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
@@ -168,7 +169,7 @@ jobs:
           - macos-14
           - macos-15
         cc:
-          - clang
+          #- clang
           - gcc
         exclude:
           # GitHub's macOS 14+ gcc can only target arm64, but Qt didn't add Apple arm64 support until Qt 6.2, so:
@@ -200,7 +201,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install lcov
-        run: brew install lcov --head # \todo Remove when lcov commit b34c844 is released.
+        run: brew install lcov@2.0 # \todo Remove when lcov commit b34c844 is released.
         # \todo See https://github.com/linux-test-project/lcov/commit/b34c84431a97b49e55785286fa05e9a95b873920
       - name: Install Qt
         uses: jurplel/install-qt-action@v4
@@ -282,7 +283,7 @@ jobs:
         if: matrix.os != 'macos-13' || matrix.cc == 'gcc'
         run: cmake --build "$RUNNER_TEMP/coverage" --target coverage
       - name: Upload test results
-        if: matrix.os != 'macos-13' || fromJSON(steps.build.outputs.tap)
+        #if: matrix.os != 'macos-13' || fromJSON(steps.build.outputs.tap)
         uses: actions/upload-artifact@v4
         with:
           name: test-results-${{ steps.build.outputs.dokitVersion }}
@@ -321,6 +322,7 @@ jobs:
           if-no-files-found: error
 
   win:
+    if: false
     runs-on: windows-latest
     defaults: { run: { shell: cmd } }
     strategy:
@@ -617,7 +619,8 @@ jobs:
           if-no-files-found: error
 
   collate-test-results:
-    needs: [ linux, mac, win ]
+    #needs: [ linux, mac, win ]
+    needs: [ mac ]
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4