Flaky test TestNativeChangeAuthTok

[adombeck]

Analysis of the last 47 runs of the go-tests-coverage job on main:

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Summary
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Total runs analyzed : 47
Runs with failures  : 2
Runs clean          : 45
Percentage failed   : 4.3%

Failure counts by test (across all runs):
──────────────────────────────────────────
    2  TestNativeChangeAuthTok
    1  TestNativeChangeAuthTok/Exit_authd_if_user_sigints
    1  TestNativeChangeAuthTok/Retry_if_new_password_is_same_of_previous

❌ run-20919503986  2026-01-12T12:33:13Z  conclusion: failure
     ❌ TestNativeChangeAuthTok
     ❌ TestNativeChangeAuthTok/Exit_authd_if_user_sigints
	Error Trace:	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:429
	            	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:418
	            	/opt/hostedtoolcache/go/1.25.5/x64/src/sync/once.go:78
	            	/opt/hostedtoolcache/go/1.25.5/x64/src/sync/once.go:69
	            	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:417
	            	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:329
	            	/home/runner/work/authd/authd/pam/integration-tests/native_test.go:612
	Error:      	Received unexpected error:
	            	open /tmp/TestNativeChangeAuthTokExit_authd_if_user_sigints311546782/001/passwd_sigint.txt: no such file or directory
	Messages:   	Could not read output file of tape "passwd_sigint" (/tmp/TestNativeChangeAuthTokExit_authd_if_user_sigints311546782/001/passwd_sigint.txt)


❌ run-20999474005  2026-01-14T15:22:32Z  conclusion: failure
     ❌ TestNativeChangeAuthTok
     ❌ TestNativeChangeAuthTok/Retry_if_new_password_is_same_of_previous
	Error Trace:	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:429
	            	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:418
	            	/opt/hostedtoolcache/go/1.25.5/x64/src/sync/once.go:78
	            	/opt/hostedtoolcache/go/1.25.5/x64/src/sync/once.go:69
	            	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:417
	            	/home/runner/work/authd/authd/pam/integration-tests/vhs-helpers_test.go:329
	            	/home/runner/work/authd/authd/pam/integration-tests/native_test.go:612
	Error:      	Received unexpected error:
	            	open /tmp/TestNativeChangeAuthTokRetry_if_new_password_is_same_of_previou3497133855/001/passwd_not_changed.txt: no such file or directory
	Messages:   	Could not read output file of tape "passwd_not_changed" (/tmp/TestNativeChangeAuthTokRetry_if_new_password_is_same_of_previou3497133855/001/passwd_not_changed.txt)