Extend go test CI from 10 to 15 miniutes

[dylandreimerink]

The default builtin timeout in the go test runner is 10 min and the GH runner is also limited to 10 min. In practice the GH runner is quicker to kill tests that exceed this time limit, in which case we abruptly exit without logs on which test caused the timeout.

This change extends the runner timeout to 15 min to give the go runner a chance to kill the bad test and to tell us which test was taking longer so that we can fix the issue.

[dylandreimerink]

Speak of the devil. This was meant for another PR but this CI run also turned up something:

=== Failed
=== FAIL: perf TestPerfReaderWakeupEvents (unknown)
panic: test timed out after 10m0s
running tests:
	TestPerfReaderWakeupEvents (10m0s)

goroutine 29 [running]:
testing.(*M).startAlarm.func1()
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:2259 +0x3b9
created by time.goFunc
	/opt/hostedtoolcache/go/1.21.8/x64/src/time/sleep.go:176 +0x2d

goroutine 1 [chan receive]:
testing.(*T).Run(0xc0000a2680, {0x71cfe6?, 0x51bbfc?}, 0x72d1a0)
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1649 +0x3c8
testing.runTests.func1(0x94c4c0?)
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:2054 +0x3e
testing.tRunner(0xc0000a2680, 0xc0000f9bd8)
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1595 +0xff
testing.runTests(0xc000090320?, {0x945f40, 0xd, 0xd}, {0xc0000f9c90?, 0x4105c9?, 0x94bbe0?})
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:2052 +0x445
testing.(*M).Run(0xc000090320)
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1925 +0x636
github.com/cilium/ebpf/internal/testutils/fdtrace.TestMain(0xc0000366f0?)
	/home/runner/work/ebpf/ebpf/internal/testutils/fdtrace/fd.go:25 +0x70
github.com/cilium/ebpf/perf.TestMain(...)
	/home/runner/work/ebpf/ebpf/perf/reader_test.go:29
main.main()
	_testmain.go:77 +0x1c7

goroutine 27 [chan receive]:
testing.(*T).Parallel(0xc00026a000)
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1403 +0x205
github.com/cilium/ebpf/perf.TestPause(0xc00026a000)
	/home/runner/work/ebpf/ebpf/perf/reader_test.go:408 +0x39
testing.tRunner(0xc00026a000, 0x72d168)
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1595 +0xff
created by testing.(*T).Run in goroutine 1
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1648 +0x3ad

goroutine 28 [syscall]:
syscall.Syscall6(0x1?, 0x77?, 0x1?, 0x97a120?, 0x77?, 0x0?, 0xc0000fba48?)
	/opt/hostedtoolcache/go/1.21.8/x64/src/syscall/syscall_linux.go:91 +0x30
golang.org/x/sys/unix.EpollWait(0x0?, {0xc0000d2150?, 0x446411?, 0xc00009a4e0?}, 0xc0000fba18?)
	/home/runner/go/pkg/mod/golang.org/x/sys@v0.15.0/unix/zsyscall_linux_amd64.go:55 +0x4f
github.com/cilium/ebpf/internal/unix.EpollWait(...)
	/home/runner/work/ebpf/ebpf/internal/unix/types_linux.go:129
github.com/cilium/ebpf/internal/epoll.(*Poller).Wait(0xc0000cc5a0, {0xc0000d2150?, 0x2, 0x2}, {0xc0000fbab0?, 0x1?, 0x0?})
	/home/runner/work/ebpf/ebpf/internal/epoll/poller.go:145 +0x2a5
github.com/cilium/ebpf/perf.(*Reader).ReadInto(0xc0000d46c0, 0x1?)
	/home/runner/work/ebpf/ebpf/perf/reader.go:362 +0x2c5
github.com/cilium/ebpf/perf.(*Reader).Read(...)
	/home/runner/work/ebpf/ebpf/perf/reader.go:336
github.com/cilium/ebpf/perf.checkRecord({0x785618, 0xc00026a1a0}, 0xf?)
	/home/runner/work/ebpf/ebpf/perf/reader_test.go:167 +0x6e
github.com/cilium/ebpf/perf.TestPerfReaderWakeupEvents(0xc00026a1a0)
	/home/runner/work/ebpf/ebpf/perf/reader_test.go:528 +0x527
testing.tRunner(0xc00026a1a0, 0x72d1a0)
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1595 +0xff
created by testing.(*T).Run in goroutine 1
	/opt/hostedtoolcache/go/1.21.8/x64/src/testing/testing.go:1648 +0x3ad

[lmb]

Thanks!