buffer: use Utf8LengthV2() instead of Utf8Length()

[tniessen]

Utf8Length() is deprecated and was replaced during the V8 update (0e68481bf82), but 084a91291e5 introduced a new occurrence.

Refs: https://github.com/nodejs/node/pull/58070 Refs: https://github.com/nodejs/node/pull/58048

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 90.17%. Comparing base (92102c0) to head (caf58f2). Report is 316 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_buffer.cc	0.00%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #58156      +/-   ##
==========================================
- Coverage   90.18%   90.17%   -0.01%     
==========================================
  Files         630      630              
  Lines      186473   186503      +30     
  Branches    36612    36613       +1     
==========================================
+ Hits       168169   168187      +18     
- Misses      11116    11121       +5     
- Partials     7188     7195       +7     

Files with missing lines	Coverage Δ
src/node_buffer.cc	68.99% <0.00%> (-0.11%)	:arrow_down:

... and 29 files with indirect coverage changes

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[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/66581/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/66594/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/66601/

[nodejs-github-bot]

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=benchmark-ubuntu2204-intel-64,v8test=v8test/6565/

[nodejs-github-bot]

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=rhel8-ppc64le,v8test=v8test/6565/

[nodejs-github-bot]

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=rhel8-s390x,v8test=v8test/6565/

[nodejs-github-bot]

Landed in 4edb139adf8da28b46a7d713b1ae69c0190e7f18

[aduh95]

Adding https://github.com/nodejs/node/labels/dont-land-on-v22%2Ex as it looks like Utf8LengthV2 is not available on 22.x.