Migrate semconv codegen to weaver

[jsuereth]

This is a prototype for discussion and demonstration in next week's Go SiG meeting.

This migrates semconv codegeneration off the (deprecated, soon to be abandoned) semconvgen to weaver.

A few things in this PR:

• We're using Weaver's automatic git resolution of tags for consuming semconv.
• We're using Weaver's acronym/synonym features instead of opentelemetry-go-build-tools
• We're directly forking docker within your makefile, including no longer running as root.

I couldn't find (easily) the documentation you had previously for generating semconv (which I did find in the collect). This should make it as easy as:

make semconv-generate TAG=v1.27.0

which is how I generated the v1.27.0 code here.

Regarding JINJA formatting, I didn't have a chance to go through whitespace refactoring/fun. For other codegen we run formatting tools as part of the makefile. I've manually run go fmt on the generated code, but we would likely want to have that a part of the Makefile to automatically correct Jinja's wierd whitespacing.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.6%. Comparing base (29c0c28) to head (6b6f9e1).
Report is 5 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #5793     +/-   ##
=======================================
- Coverage   84.6%   84.6%   -0.1%     
=======================================
  Files        272     272             
  Lines      22759   22778     +19     
=======================================
+ Hits       19255   19271     +16     
- Misses      3164    3166      +2     
- Partials     340     341      +1     

see 1 file with indirect coverage changes