refactor(instr-socket.io): use exported strings for attributes

[david-luna]

Which problem is this PR solving?

• Updates Update usage of semantic conventions to new exported strings #2025

Short description of the changes

• Update @opentelemetry/semantic-conventions to ^1.22
• Replace SemanticAttributes.* with exported strings SEMATTRS_*
• Update README with new semantic convention package version and key

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.45%. Comparing base (dfb2dff) to head (8f01503).
Report is 82 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2147      +/-   ##
==========================================
- Coverage   90.97%   90.45%   -0.53%     
==========================================
  Files         146      147       +1     
  Lines        7492     7576      +84     
  Branches     1502     1574      +72     
==========================================
+ Hits         6816     6853      +37     
- Misses        676      723      +47     

see 25 files with indirect coverage changes