[GA] more c++17 fixes

almalinux:
- install gcc-toolset-11
i386-linux, x86_64-linux(musl)
- add -std=c++17 CXXFLAG

git-svn-id: svn://tug.org/texlive/trunk/Build/source@72687 c570f23f-e606-0410-a88d-b1316a301751

.github/scripts/build-tl.sh

@@ -34,8 +34,8 @@ then
        ;;
      almalinux)
        yum update -y
-       yum install -y gcc-toolset-9 fontconfig-devel libX11-devel libXmu-devel libXaw-devel
-       . /opt/rh/gcc-toolset-9/enable
+       yum install -y gcc-toolset-11 fontconfig-devel libX11-devel libXmu-devel libXaw-devel
+       . /opt/rh/gcc-toolset-11/enable
        ;;
      centos)
        yum update -y
@@ -121,7 +121,7 @@ case "$arch" in
     export CFLAGS=-D_NETBSD_SOURCE
     export CXXFLAGS='-D_NETBSD_SOURCE -std=c++17'
     ;;
-  i386-linux)
+  x86_64-linux|i386-linux|x86_64-linuxmusl)
     export CXXFLAGS='-std=c++17'
     ;;
 esac