chore(ci): limit number of parallel builds to prevent runner resource starvation (#6683)

.github/workflows/build_fw.yml

@@ -73,11 +73,11 @@ jobs:
       - name: Test ${{ matrix.target }}
         env:
           FLAVOR: ${{ matrix.target }}
+          CMAKE_BUILD_PARALLEL_LEVEL: 4
         run: |
           echo "Running commit tests"
           ./tools/commit-tests.sh
 
-
   build:
     name: Run builds
     needs: test
@@ -123,6 +123,7 @@ jobs:
       - name: Build ${{ matrix.target }}
         env:
           FLAVOR: ${{ matrix.target }}
+          CMAKE_BUILD_PARALLEL_LEVEL: 4
         run: |
           echo "Running firmware build"
           ./tools/build-gh.sh

.github/workflows/linux_cpn.yml

@@ -45,6 +45,8 @@ jobs:
       - name: Build
         working-directory: ${{github.workspace}}
         shell: bash
+        env:
+          CMAKE_BUILD_PARALLEL_LEVEL: 4
         run: |
           mkdir output && mkdir logs && \
           tools/build-companion.sh "$(pwd)" "$(pwd)/output/" 2>&1 | tee logs/build-main.log

.github/workflows/macosx_cpn.yml

@@ -73,6 +73,8 @@ jobs:
       - name: Build
         working-directory: ${{github.workspace}}
         shell: bash
+        env:
+          CMAKE_BUILD_PARALLEL_LEVEL: 3
         run: |
           mkdir output && mkdir logs && \
           tools/build-companion.sh "$(pwd)" "$(pwd)/output/" 2>&1 | tee logs/build-main.log

.github/workflows/nightly.yml

@@ -51,6 +51,7 @@ jobs:
         env:
           FLAVOR: ${{ matrix.target }}
           EDGETX_VERSION_SUFFIX: nightly
+          CMAKE_BUILD_PARALLEL_LEVEL: 4
         run: ./tools/build-gh.sh
 
       - name: Package firmware ${{ matrix.target }}

.github/workflows/win_cpn-64.yml

@@ -74,6 +74,8 @@ jobs:
         uses: ilammy/msvc-dev-cmd@v1
 
       - name: Build
+        env:
+          CMAKE_BUILD_PARALLEL_LEVEL: 4
         run: |
           mkdir output && mkdir logs && \
           CMAKE_PREFIX_PATH="$QT_ROOT_DIR;$SDL2_ROOT" \