cmake: Update to 3.20.2

cmake: Update to 3.20.2

- Update from 3.20.0 to 3.20.2
- Update rootfile
- Changelog
   3.20.1
     -The FindIntl module in CMake 3.20.0 added checks
      Intl_HAVE_GETTEXT_BUILTIN, Intl_HAVE_DCGETTEXT_BUILTIN, and
      Intl_IS_BUILTIN, but they were not implemented correctly. These have
      been removed and replaced with a single Intl_IS_BUILT_IN check, whose
      name is consistent with the FindIconv module.
     -The -rpath linker flag is now specified as supported on all Apple
      platforms, not just macOS. The install_name_dir used for iOS, tvOS
      and watchOS should now default to @rpath instead of using a full
      absolute path and failing at runtime when the library or framework
      is embedded in an application bundle (see XCODE_EMBED_<type>).
   3.20.2
     -The Intel Classic 2021 compiler version numbers are now detected
      correctly as having major version 2021. CMake 3.20.1 and below were
      not aware of a change to the identification macro version scheme
      made by Intel starting in version 2021, and detected the version
      as 20.2.
     -The Intel oneAPI Fortran compiler is now identified as IntelLLVM.
      The oneAPI 2021.1 Fortran compiler is missing an identification
      macro, so CMake 3.20.1 and below identified it as Intel. CMake now
      has a special case to recognize oneAPI 2021.1 Fortran as IntelLLVM.
      The oneAPI 2021.2 Fortran compiler defines the proper identification
      macro and so is identified as IntelLLVM by all CMake 3.20 versions.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>