Upgrade ubuntu-20.04 jobs (#743)

As per actions/runner-images#11101, the
`ubuntu-20.04` pool is going to the GitHub Graveyard.

Author: dscho

.github/workflows/main.yml

@@ -449,20 +449,11 @@ jobs:
     if: needs.ci-config.outputs.enabled == 'yes'
     env:
       jobname: sparse
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     concurrency:
       group: sparse-${{ github.ref }}
       cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
-    - name: Download a current `sparse` package
-      # Ubuntu's `sparse` version is too old for us
-      uses: git-for-windows/get-azure-pipelines-artifact@v0
-      with:
-        repository: git/git
-        definitionId: 10
-        artifact: sparse-20.04
-    - name: Install the current `sparse` package
-      run: sudo dpkg -i sparse-20.04/sparse_*.deb
     - uses: actions/checkout@v4
     - name: Install other dependencies
       run: ci/install-dependencies.sh

.github/workflows/scalar-functional-tests.yml

@@ -20,15 +20,13 @@ jobs:
       fail-fast: false
       matrix:
         # Order by runtime (in descending order)
-        os: [windows-2019, macos-13, ubuntu-20.04, ubuntu-22.04]
+        os: [windows-2019, macos-13, ubuntu-22.04]
         # Scalar.NET used to be tested using `features: [false, experimental]`
         # But currently, Scalar/C ignores `feature.scalar` altogether, so let's
         # save some electrons and run only one of them...
         features: [ignored]
         exclude:
           # The built-in FSMonitor is not (yet) supported on Linux
-          - os: ubuntu-20.04
-            features: experimental
           - os: ubuntu-22.04
             features: experimental
     runs-on: ${{ matrix.os }}

Makefile

@@ -1424,7 +1424,7 @@ ARFLAGS = rcs
 PTHREAD_CFLAGS =
 
 # For the 'sparse' target
-SPARSE_FLAGS ?= -std=gnu99
+SPARSE_FLAGS ?= -std=gnu99 -D__STDC_NO_VLA__
 SP_EXTRA_FLAGS =
 
 # For informing GIT-BUILD-OPTIONS of the SANITIZE=leak,address targets

ci/install-dependencies.sh

@@ -119,7 +119,7 @@ StaticAnalysis)
 sparse)
 	sudo apt-get -q update -q
 	sudo apt-get -q -y install libssl-dev libcurl4-openssl-dev \
-		libexpat-dev gettext zlib1g-dev
+		libexpat-dev gettext zlib1g-dev sparse
 	;;
 Documentation)
 	sudo apt-get -q update