Tidy go-vcr usage

[theunrepentantgeek]

What this PR does

Reduces the number of permitted replays of GET requests significantly, which help with faster test failures if/when things go wrong.

Also removes the now unused v3 of our internal vcr package, given that v4 appears reliable.

Closes #5282
Closes #5109

Special notes

We used to need effectively unlimited replays, now we seem to get by with far fewer.

How does this PR make you feel?

[Copilot]

Pull request overview

This PR tidies the internal go-vcr integration used by ASO v2 tests by tightening replay behavior and removing the legacy v3 implementation now that v4 is considered stable.

Changes:

• Reduce the allowed number of GET replays during cassette playback (faster failure when recordings diverge).
• Remove the internal v2/internal/testcommon/vcr/v3 implementation and its associated tests/recording.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
v2/internal/testcommon/vcr/v4/replay_roundtripper.go	Lowers the GET replay limit used by the v4 replay round-tripper.
v2/internal/testcommon/vcr/v3/tracking_roundtripper.go	Removes legacy v3 tracking header round-tripper implementation.
v2/internal/testcommon/vcr/v3/error_translating_roundtripper.go	Removes legacy v3 error translation wrapper.
v2/internal/testcommon/vcr/v3/replay_roundtripper.go	Removes legacy v3 replay round-tripper implementation.
v2/internal/testcommon/vcr/v3/replay_roundtripper_test.go	Removes legacy v3 replay round-tripper tests.
v2/internal/testcommon/vcr/v3/test_recorder.go	Removes legacy v3 test recorder implementation.
v2/internal/testcommon/vcr/v3/test_recorder_test.go	Removes legacy v3 test recorder tests.
v2/internal/testcommon/vcr/v3/recordings/TestRecorder_WhenRecordingAndRecordingExists_DoesPlayback.yaml	Removes legacy v3 test cassette recording.