Don't fail if there is no _context_manager_state

[sentrivana]

Root cause fix to follow once we figure it out. This PR just makes the SDK not boom.

If we manage to fix the root cause before the next release, this PR is not necessary.

[cursor]

Bug: Context Manager Exception Handling Flaw

The __exit__ method's capture_internal_exceptions() block is overly broad. It silently swallows exceptions from self.stop(), masking legitimate bugs. Additionally, if accessing _context_manager_state fails, the subsequent scope restoration (scope.profile = old_profile) is skipped, leaving the scope referencing a stopped profile and creating an inconsistent state.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.11%. Comparing base (1804955) to head (6b923fe).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4698      +/-   ##
==========================================
+ Coverage   85.07%   85.11%   +0.04%     
==========================================
  Files         156      156              
  Lines       15984    15985       +1     
  Branches     2718     2718              
==========================================
+ Hits        13598    13606       +8     
+ Misses       1600     1594       -6     
+ Partials      786      785       -1     

Files with missing lines	Coverage Δ
sentry_sdk/profiler/transaction_profiler.py	87.46% <100.00%> (+1.53%)	⬆️

... and 2 files with indirect coverage changes