[Bugfix] Set shell idle when message skipped by "should_handle" in "dispatch_shell" #3300

Job	Run time
Test Lint	59s
check_release	1m 41s
build (ubuntu-latest, 3.9)	3m 3s
Make SDist	19s
test_docs	41s
build (ubuntu-latest, 3.13)	2m 59s
Test Minimum Versions	2m 9s
build (windows-latest, 3.9)	6m 32s
Test Prereleases	1m 47s
test_without_debugpy (ubuntu-latest, 3.9)	1m 43s
build (windows-latest, 3.13)	7m 16s
build (macos-latest, 3.9)	4m 45s
link_check	3m 29s
build (macos-latest, 3.13)	4m 38s
build (ubuntu-latest, pypy-3.9)	4m 6s
build (macos-latest, 3.10)	4m 25s
build (ubuntu-latest, 3.11)	2m 56s
build (ubuntu-latest, 3.12)	3m 13s
Install from SDist and Test	1m 44s
coverage	8s
	58m 33s

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