set DCMAKE_TOOLCHAIN_FILE to none in extraction

currently, it instantly fails as that path does not exist.

.github/workflows/ccpp.yml

@@ -34,7 +34,7 @@ jobs:
       run: |
         mkdir build_dir
         cd build_dir
-        cmake ../ || true     # we know this will fail, we just need version info from CMakeCache.txt
+        cmake -DCMAKE_TOOLCHAIN_FILE="" ../ || true     # we know this will fail, we just need version info from CMakeCache.txt
         TF2BD_VERSION_NOBUILD=`cat CMakeCache.txt | grep TF2BD_VERSION_NOBUILD: | cut -d "=" -f2`
         echo "::set-output name=value::$TF2BD_VERSION_NOBUILD.${{ github.run_number }}"
 
@@ -172,4 +172,4 @@ jobs:
       with:
         name: "tf2-bot-detector-symbols_${{ matrix.triplet }}_${{ needs.config.outputs.tf2bd_version }}_${{ matrix.build_type }}"
         if-no-files-found: error
-        path: "${{ needs.config.outputs.tf2bd_build_dir }}/**.pdb"
+        path: "${{ needs.config.outputs.tf2bd_build_dir }}/**.pdb"