Rocky8: Add scl-gcc-toolset/{9,10,11,12} modules

[HenrikBengtsson]

[devr8]$ scl list-collections
gcc-toolset-10
gcc-toolset-11
gcc-toolset-12
gcc-toolset-9

Default GCC is:

[devr8]$ gcc --version
gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-18)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[HenrikBengtsson]

Added.