chore(deps): update actions/checkout action to v4 #661

Job	Run time
Publish Charm / Generate the Charm Matrix	5s
Run Tests / Integration tests (microk8s) (katib-controller)	44m 23s
Run Tests / Integration tests (microk8s) (katib-db-manager)	39m 26s
Run Tests / Lint	12s
Run Tests / Test the bundle	1h 51m 45s
Run Tests / Unit tests (katib-controller)	20s
Run Tests / Unit tests (katib-db-manager)	14s
Run Tests / Check libraries (katib-controller) / Check libraries	2m 48s
Run Tests / Check libraries (katib-controller) / Lint	10s
Run Tests / Check libraries (katib-db-manager) / Check libraries	28s
Run Tests / Check libraries (katib-db-manager) / Lint	9s
Run Tests / Check libraries (katib-ui) / Check libraries	2m 0s
Run Tests / Check libraries (katib-ui) / Lint	8s
Publish Charm / Publish Charm (./charms/katib-ui)	21m 44s
Publish Charm / Publish Charm (./charms/katib-db-manager)	33m 39s
Publish Charm / Publish Charm (./charms/katib-controller)	33m 42s
	4h 51m 13s

Provide feedback