Add attempt number to activity logger

[evansandoval]

Detailed Description
Adds attempt number to structured logs within WithActivityTask in activity.go and executeLocalActivityTask in internal_task_pollers.go.

Impact Analysis

• Backward Compatibility: No changes to core Cadence functionality or public API's / data structures.
• Forward Compatibility: Uses existing fields and doesn't introduce any new dependencies.

Testing Plan

• Unit Tests: Existing unit tests continue to pass.
• Persistence Tests: No changes to persisted data structures.
• Integration Tests: Existing tests continue to pass (activity execution behaviors are unchanged)
• Compatibility Tests: Existing tests continue to pass (activity execution behaviors are unchanged)

Rollout Plan

• What is the rollout plan?
  • Standard rollout / deployment process
• Does the order of deployment matter?
  • No specific order required.
• Is it safe to rollback? Does the order of rollback matter?
  • Completely safe to rollback, no specific order required either.
• Is there a kill switch to mitigate the impact immediately?
  • Not needed as no business logic changes. Can simply rollback the commit.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.21%. Comparing base (3d6e75c) to head (5ba310e).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Coverage Δ
internal/activity.go	90.00% <100.00%> (+0.09%)	⬆️
internal/internal_task_pollers.go	82.88% <100.00%> (-0.28%)	⬇️

... and 1 file with indirect coverage changes

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[Groxx]

👍 yep, looks good. GetAttempt() is reasonable here regardless of whether it always exists or not, these retry fields are a bit fiddly sometimes and this does seem better safe than sorry.