runtime: TestFinalizerOrCleanupDeadlock/Panic failures

[gopherbot]

#!watchflakes
default <- pkg == "runtime" && test == "TestFinalizerOrCleanupDeadlock/Panic"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestFinalizerOrCleanupDeadlock/Panic
=== PAUSE TestFinalizerOrCleanupDeadlock/Panic
=== CONT  TestFinalizerOrCleanupDeadlock/Panic
    crash_test.go:1164: /home/swarming/.swarming/w/ir/x/t/go-build3963371700/testprog.exe FinalizerDeadlock: exit status 2
    crash_test.go:1167: output does not contain "runtime.runFinalizers()":
        panic: panic
        
        goroutine 1 [running]:
        main.FinalizerOrCleanupDeadlock(0x0)
        	/home/swarming/.swarming/w/ir/x/w/goroot/src/runtime/testdata/testprog/finalizer_deadlock.go:48 +0x51a
        main.init.8.func1()
        	/home/swarming/.swarming/w/ir/x/w/goroot/src/runtime/testdata/testprog/finalizer_deadlock.go:18 +0x15
        main.main()
        	/home/swarming/.swarming/w/ir/x/w/goroot/src/runtime/testdata/testprog/main.go:34 +0x133
        
        goroutine 7 [running]:
        	goroutine running on other thread; stack unavailable
--- FAIL: TestFinalizerOrCleanupDeadlock/Panic (0.13s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime" && test == "TestFinalizerOrCleanupDeadlock/Panic"

2025-06-30 16:31 go1.25-linux-amd64-clang15 release-branch.go1.25@47318323 runtime.TestFinalizerOrCleanupDeadlock/Panic (log)

=== RUN   TestFinalizerOrCleanupDeadlock/Panic
=== PAUSE TestFinalizerOrCleanupDeadlock/Panic
=== CONT  TestFinalizerOrCleanupDeadlock/Panic
    crash_test.go:1164: /home/swarming/.swarming/w/ir/x/t/go-build3963371700/testprog.exe FinalizerDeadlock: exit status 2
    crash_test.go:1167: output does not contain "runtime.runFinalizers()":
        panic: panic
        
        goroutine 1 [running]:
        main.FinalizerOrCleanupDeadlock(0x0)
        	/home/swarming/.swarming/w/ir/x/w/goroot/src/runtime/testdata/testprog/finalizer_deadlock.go:48 +0x51a
        main.init.8.func1()
        	/home/swarming/.swarming/w/ir/x/w/goroot/src/runtime/testdata/testprog/finalizer_deadlock.go:18 +0x15
        main.main()
        	/home/swarming/.swarming/w/ir/x/w/goroot/src/runtime/testdata/testprog/main.go:34 +0x133
        
        goroutine 7 [running]:
        	goroutine running on other thread; stack unavailable
--- FAIL: TestFinalizerOrCleanupDeadlock/Panic (0.13s)

— watchflakes