flake: `TestExpRpty/Container`

[dannykopping]

    ptytest.go:167: 2025-12-04 09:41:17.924: cmd: read error: match deadline exceeded: context deadline exceeded (wanted " #"; got "")
    ptytest.go:167: 
        	Error Trace:	/home/runner/work/coder/coder/pty/ptytest/ptytest.go:372
        	            				/home/runner/work/coder/coder/pty/ptytest/ptytest.go:196
        	            				/home/runner/work/coder/coder/pty/ptytest/ptytest.go:167
        	            				/home/runner/work/coder/coder/pty/ptytest/ptytest.go:162
        	            				/home/runner/work/coder/coder/pty/ptytest/ptytest.go:149
        	            				/home/runner/work/coder/coder/cli/exp_rpty_test.go:136
        	Error:      	read error
        	Test:       	TestExpRpty/Container
        	Messages:   	match deadline exceeded: context deadline exceeded (wanted " #"; got "")

Seen in https://github.com/coder/coder/actions/runs/19924364267/job/57120337027