feat: non-experimental enable_metrics option

[alexander-alderman-webb]

Description

Add a toggle for metrics in the form of an enable_metrics flag that defaults to True.

The PR is not undoing #5046 because

• the new flag default to True; and
• the new flag is a stable top level option as per the spec: docs(dev-docs): Add metrics telemetry specs sentry-docs#15178

Issues

Reminders

• Please add tests to validate your changes, and lint your code using tox -e linters.
• Add GH Issue ID & Linear ID (if applicable)
• PR title should use conventional commit style (feat:, fix:, ref:, meta:)
• For external contributors: CONTRIBUTING.md, Sentry SDK development docs, Discord community

[codecov]

Codecov Report

❌ Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.93%. Comparing base (8965821) to head (58a65d2).
⚠️ Report is 5 commits behind head on master.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
sentry_sdk/utils.py	50.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@ Coverage Diff @@## master #5056 +/- ## ========================================== - Coverage 83.96% 83.93% -0.03%  ========================================== Files 179 179 Lines 17894 17900 +6 Branches 3177 3179 +2 ========================================== Hits 15024 15024 - Misses 1900 1907 +7 + Partials 970 969 -1 

Files with missing lines	Coverage Δ
sentry_sdk/client.py	84.09% <100.00%> (+0.44%)	⬆️
sentry_sdk/consts.py	99.40% <ø> (ø)
sentry_sdk/utils.py	86.25% <50.00%> (-0.17%)	⬇️

... and 3 files with indirect coverage changes

[cursor]

Bug: Metrics toggle ignores experimental flag, breaking compatibility

The has_metrics_enabled function only checks the top-level enable_metrics option, ignoring the experimental _experiments.enable_metrics option. This breaks backward compatibility for users disabling metrics through the experimental flag.

[alexander-alderman-webb]

Yes, but I couldn't think of a good way to combine them because the experimental option defaulted to False and the stable option defaults to True.