Fixed JSON encoding of importance used as keys #640

Job	Run time
cancel-previous-runs	2s
assess-file-changes / Test changed-files	7s
run-doc-link-checks / Testing External Links	57s
run-past-gallery / Testing against past PyNWB versions (2.1.0)	2m 45s
run-past-gallery / Testing against past PyNWB versions (2.0.0)	3m 21s
run-streaming-tests / Streaming tests using ubuntu-latest with 3.8	6m 16s
run-streaming-tests / Streaming tests using ubuntu-latest with 3.11	6m 14s
run-streaming-tests / Streaming tests using macos-latest with 3.8	13m 53s
run-streaming-tests / Streaming tests using macos-latest with 3.11	14m 48s
run-streaming-tests / Streaming tests using windows-latest with 3.8	10m 39s
run-streaming-tests / Streaming tests using windows-latest with 3.11	12m 24s
run-tests / Testing using ubuntu-latest with 3.8	4m 25s
run-tests / Testing using ubuntu-latest with 3.11	4m 6s
run-tests / Testing using macos-latest with 3.8	8m 26s
run-tests / Testing using macos-latest with 3.11	7m 8s
run-tests / Testing using windows-latest with 3.8	12m 40s
run-tests / Testing using windows-latest with 3.11	10m 38s
run-dev-gallery / Testing against dev PyNWB version	3m 53s
test-dandi-dev / Testing against current DANDI release and dev branch	15m 56s
test-dandi-latest / Testing against current DANDI release and dev branch	20m 18s
All tests passing	3s
	2h 38m 59s

Provide feedback