Drop VSS from GitHub CI scripts

because VSS is provided by libadalang binaries now.

(no-issue-check)

.github/workflows/build-binaries.sh

@@ -33,7 +33,6 @@ fi
 
 export GPR_PROJECT_PATH=$prefix/share/gpr:\
 $prefix/$TARGET/share/gpr:\
-$PWD/subprojects/VSS/gnat:\
 $PWD/subprojects/gnatdoc/gnat:\
 $PWD/subprojects/lal-refactor/gnat:\
 $PWD/subprojects/libadalang-tools/src:\

.github/workflows/build-binaries.yml

@@ -75,11 +75,6 @@ jobs:
         uses: actions/checkout@v3
         with:
           fetch-depth: 0
-      - name: Get VSS
-        uses: actions/checkout@v3
-        with:
-          repository: AdaCore/VSS
-          path: subprojects/VSS
       - name: Get Spawn
         uses: actions/checkout@v3
         with: