Add tests for `LocalEventManager` #70

Job	Run time
Run type checking / Type checking (3.9)	37s
Run linting / Linting (3.9)	31s
Run type checking / Type checking (3.10)	35s
Run unit tests / Unit tests (ubuntu-latest, 3.9)	30s
Check changelog entry / Check changelog entry	37s
Run linting / Linting (3.10)	31s
Run type checking / Type checking (3.11)	34s
Run unit tests / Unit tests (ubuntu-latest, 3.10)	32s
Run linting / Linting (3.11)	28s
Run type checking / Type checking (3.12)	30s
Run unit tests / Unit tests (ubuntu-latest, 3.11)	29s
Run linting / Linting (3.12)	30s
Check version conflict / Check version conflict	29s
Run unit tests / Unit tests (ubuntu-latest, 3.12)	33s
Run unit tests / Unit tests (windows-latest, 3.9)	1m 59s
Run unit tests / Unit tests (windows-latest, 3.10)	2m 7s
Run unit tests / Unit tests (windows-latest, 3.11)	2m 19s
Run unit tests / Unit tests (windows-latest, 3.12)	1m 28s
	15m 19s

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