Check context prior to delaying retry in OTLP exporters

[MrAlias]

Fix #7673

Issue being addressed:

1. fn is called
2. It returns an error
3. The code checks if the error is retryable, it always is
4. Time delay is checked
   • Max elsapsed time is 10 ms
   • Initial delay is 1ms
   • Delay is determined to be 1ms
   • The program proceeds to waiting
5. Wait is called
6. The wait select statement is evaluated
   • On slow systems both cases are true
     • Non-deterministically the timer channel case is selected
     • The retry function is re-run and and second iteration is recorded causing the failure
   • On fast systems only the context cancel is true
     • The retry stops here with only 1 execution

Do not rely on non-deterministic select statement to catch ended context prior to waiting for a retry delay. Explicitly check the context prior to entering the wait.

This resolves the flaky test and ensure in normal operation that requests with canceled context are ended without having to wait for any additional delays.

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.0%. Comparing base (61765e7) to head (fedaeb3).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
...s/otlp/otlplog/otlploggrpc/internal/retry/retry.go	50.0%	0 Missing and 1 partial ⚠️
...s/otlp/otlplog/otlploghttp/internal/retry/retry.go	50.0%	0 Missing and 1 partial ⚠️
.../otlpmetric/otlpmetricgrpc/internal/retry/retry.go	50.0%	0 Missing and 1 partial ⚠️
.../otlpmetric/otlpmetrichttp/internal/retry/retry.go	50.0%	0 Missing and 1 partial ⚠️
...lp/otlptrace/otlptracegrpc/internal/retry/retry.go	50.0%	0 Missing and 1 partial ⚠️
...lp/otlptrace/otlptracehttp/internal/retry/retry.go	50.0%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #7678     +/-   ##
=======================================
- Coverage   86.1%   86.0%   -0.2%     
=======================================
  Files        298     298             
  Lines      21709   21727     +18     
=======================================
- Hits       18707   18696     -11     
- Misses      2625    2630      +5     
- Partials     377     401     +24     

Files with missing lines	Coverage Δ
...s/otlp/otlplog/otlploggrpc/internal/retry/retry.go	86.0% <50.0%> (-11.5%)	⬇️
...s/otlp/otlplog/otlploghttp/internal/retry/retry.go	86.0% <50.0%> (-11.5%)	⬇️
.../otlpmetric/otlpmetricgrpc/internal/retry/retry.go	86.0% <50.0%> (-11.5%)	⬇️
.../otlpmetric/otlpmetrichttp/internal/retry/retry.go	86.0% <50.0%> (-11.5%)	⬇️
...lp/otlptrace/otlptracegrpc/internal/retry/retry.go	86.0% <50.0%> (-11.5%)	⬇️
...lp/otlptrace/otlptracehttp/internal/retry/retry.go	86.0% <50.0%> (-11.5%)	⬇️

... and 1 file with indirect coverage changes

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[Copilot]

Pull request overview

This PR adds explicit context cancellation checks to OTLP exporters' retry logic to eliminate reliance on non-deterministic select statement behavior. The change ensures requests with canceled contexts fail immediately without waiting for retry delays, fixing a flaky test issue.

• Adds ctx.Err() check immediately after determining an error is retryable but before attempting any retry delay
• Uses consistent error wrapping pattern fmt.Errorf("%w: %w", ctx.Err(), err) to preserve both the context error and original error
• Applied uniformly across all OTLP exporter variants (trace/metric/log over HTTP/gRPC)

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/shared/otlp/retry/retry.go.tmpl	Template source adding context check before retry wait logic
exporters/otlp/otlptrace/otlptracehttp/internal/retry/retry.go	Generated file for HTTP trace exporter with context check
exporters/otlp/otlptrace/otlptracegrpc/internal/retry/retry.go	Generated file for gRPC trace exporter with context check
exporters/otlp/otlpmetric/otlpmetrichttp/internal/retry/retry.go	Generated file for HTTP metric exporter with context check
exporters/otlp/otlpmetric/otlpmetricgrpc/internal/retry/retry.go	Generated file for gRPC metric exporter with context check
exporters/otlp/otlplog/otlploghttp/internal/retry/retry.go	Generated file for HTTP log exporter with context check
exporters/otlp/otlplog/otlploggrpc/internal/retry/retry.go	Generated file for gRPC log exporter with context check

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[bboreham]

I'd like to suggest using context.Cause() here, which could make the error more useful.

It is already used in this file, from #6898.

I made a PR: #7811