Increase the character limit of the Meter instrument name

[B3zaleel]

Design discussion issue #4774

Changes

Changed the limit of the instrument name regex from 63 to 255 as specified here in the Open Telemetry metrics API specification.

Merge requirement checklist

• CONTRIBUTING guidelines followed (nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: B3zaleel / name: Bezaleel Olakunori (6477c3b, 1d15d75)

[codecov]

Codecov Report

Merging #4798 (1d15d75) into main (0d1cc36) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4798      +/-   ##
==========================================
- Coverage   85.60%   85.58%   -0.02%     
==========================================
  Files         284      284              
  Lines       11686    11686              
==========================================
- Hits        10004    10002       -2     
- Misses       1682     1684       +2     

Files Changed	Coverage Δ
...lemetry/Metrics/Builder/MeterProviderBuilderSdk.cs	95.08% <100.00%> (ø)

... and 2 files with indirect coverage changes

[cijothomas]

Thanks! LGTM. Please add an entry to changelog.md file as this is user facing change.

[Yun-Ting]

LGTM, Thanks!

[Yun-Ting]

Just saw a typo from the PR description:
"Changed the limit of the instrument name regex from 63 to 244 as specified"
should be 254 instead of 244.

[B3zaleel]

Just saw a typo from the PR description: "Changed the limit of the instrument name regex from 63 to 244 as specified" should be 254 instead of 244.

@Yun-Ting Thanks. I adjusted the description.