Bazel build: Update of skylib

[Vertexwahn]

This PR only affects the Bazel Build of Catch2.

• Update of skylib
• Add config for gcc11
• Remove not needed load of cc_rules

[codecov[bot]]

Codecov Report

Merging #2528 (072a1c7) into devel (c0e582e) will decrease coverage by 0.19%. The diff coverage is n/a.

@@            Coverage Diff             @@
##            devel    #2528      +/-   ##
==========================================
- Coverage   91.75%   91.56%   -0.19%     
==========================================
  Files         183      183              
  Lines        7476     7560      +84     
==========================================
+ Hits         6859     6922      +63     
- Misses        617      638      +21     

[Vertexwahn]

@horenmar Can you please review?

[Vertexwahn]

@horenmar Currently the Bazel build of Catch2 is broken. This PR is going to fix this (proper handing of CATCH_CONFIG_SHARED_LIBRARY)