interp: skip TestRunnerTerminalExec/Pseudo on all OSs
interp: skip TestRunnerTerminalExec/Pseudo on all OSs

Just got a failure on ubuntu-latest. The same error as Mac:

	--- FAIL: TestRunnerTerminalExec (0.00s)
	    --- FAIL: TestRunnerTerminalExec/Pseudo (0.03s)
	##[error]        terminal_test.go:133: signal: hangup
	FAIL

Updates #513.

mvdan/sh,mvdan/sh,mvdan/sh,mvdan/sh