fix(input): keep pending url clicks across host focus loss (#2291)

Opening a URL raises the browser, which takes focus away from the host
terminal before the mouse release arrives. release_input_source(_headless)
cleared pending_url_click_sources on that focus loss, so the release was
forwarded to the pane and the agent opened the same URL again.

Clear the set in clear_input_source instead, whose only production caller
is remove_client.

refs #2290

Co-authored-by: kataokatsuki <kataokatsuki@users.noreply.github.com>

0 files changed, 0 insertions, 0 deletions