chore(deps): update actions/upload-artifact action to v4 #966

Job	Run time
Publish Charm / Generate the Charm Matrix	3s
Run Tests / Individual charm's integration tests (controller)	17m 39s
Run Tests / Unit Test (controller)	30s
Run Tests / Bundle Integration	20m 37s
Run Tests / Unit Test (ui)	29s
Run Tests / Individual charm's integration tests (ui)	17m 21s
Run Tests / Lint Code (controller)	21s
Run Tests / Lint Code (ui)	23s
Run Tests / Check libraries (jupyter-controller) / Check libraries	32s
Run Tests / Check libraries (jupyter-controller) / Lint	11s
Run Tests / Check libraries (jupyter-ui) / Check libraries	36s
Run Tests / Check libraries (jupyter-ui) / Lint	8s
Run Tests / Terraform (controller) / Lint Terraform	9s
Run Tests / Terraform (ui) / Lint Terraform	9s
Run Tests / Terraform (controller) / Apply / Apply Terraform	5m 3s
Run Tests / Terraform (ui) / Apply / Apply Terraform	5m 52s
Run Tests / Terraform (controller) / Check / Check Terraform	5s
Run Tests / Terraform (ui) / Check / Check Terraform	9s
Publish Charm / Publish Charm (./charms/jupyter-ui)	7m 11s
Publish Charm / Publish Charm (./charms/jupyter-controller)	7m 8s
	1h 24m 36s

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