chore(examples/express): use exported strings for attributes

[maryliag]

Which problem is this PR solving?

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

Short description of the changes

On package examples/express:

• Update @opentelemetry/semantic-conventions ^1.23.0
• Use exported strings for Semantic Attributes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.35%. Comparing base (dfb2dff) to head (152ca80).
Report is 82 commits behind head on main.

❗ Current head 152ca80 differs from pull request most recent head 299cff4. Consider uploading reports for the commit 299cff4 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2121      +/-   ##
==========================================
- Coverage   90.97%   90.35%   -0.63%     
==========================================
  Files         146      147       +1     
  Lines        7492     7679     +187     
  Branches     1502     1575      +73     
==========================================
+ Hits         6816     6938     +122     
- Misses        676      741      +65     

see 10 files with indirect coverage changes

[jarias-lfx]

/easycla