Update toolchain for linux builds

Signed-off-by: falkTX <[email protected]>

.github/workflows/build.yml

@@ -3,7 +3,7 @@ name: build
 on: [push, pull_request]
 
 env:
-  CACHE_VERSION_LINUX: 4
+  CACHE_VERSION_LINUX: 5
   CACHE_VERSION_MACOS: 3
   CACHE_VERSION_WIN64: 3
   DEBIAN_FRONTEND: noninteractive
@@ -15,13 +15,19 @@ jobs:
     container:
       image: ubuntu:18.04
     steps:
-      - name: Update git
+      - name: Update git and toolchain
         run: |
-          apt-get update -qq && apt-get install -yqq curl git libpcre2-8-0
+          apt-get update -qq && apt-get install -yqq --no-install-recommends curl git libpcre2-8-0 software-properties-common
+          add-apt-repository -y ppa:ubuntu-toolchain-r/test
+          apt-get install -yqq g++-11
           curl -sLO https://launchpad.net/~kxstudio-debian/+archive/ubuntu/toolchain/+files/git_2.34.1-1ubuntu1~bpo18.04.1~ppa1_amd64.deb
           curl -sLO https://launchpad.net/~kxstudio-debian/+archive/ubuntu/toolchain/+files/git-man_2.34.1-1ubuntu1~bpo18.04.1~ppa1_all.deb
           dpkg -i *.deb
           rm *.deb
+          update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 60 --slave /usr/bin/g++ g++ /usr/bin/g++-11
+          echo "CC=/usr/bin/gcc-11" >> "${GITHUB_ENV}"
+          echo "CPP=/usr/bin/cpp-11" >> "${GITHUB_ENV}"
+          echo "CXX=/usr/bin/g++-11" >> "${GITHUB_ENV}"
       - uses: actions/checkout@v3
         with:
           submodules: recursive