Pop to originating erc buffer when clicking desktop notification

* lisp/erc/erc-desktop-notifications.el: Switch to lexical-binding.
(erc-notifications-notify): Add a default action to the desktop
notification which pops to the buffer from which the notification
originated.  (Bug#35141)

Copyright-paperwork-exempt: yes
1 job for master in 49 minutes and 40 seconds (queued for 3 seconds)
Status Job ID Name Coverage
failed #1319


Name Stage Failure
test-all Test
Makefile:313: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:288: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:962: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1