chore(quay): enable knip reports and remove unused dependencies

[dzemanov]

Hey, I just made a Pull Request!

• enable knip reports and remove unused dependencies
• removes optional apiKey from app-config.yaml since it can not be empty
  • to fix: Invalid type in config for key 'quay.apiKey' in 'app-config.yaml', got empty-string, wanted string

✔️ Checklist

• A changeset describing the change and affected packages. (more info)
• Added or updated documentation
• Tests for new functionality and regression tests for bug fixes
• Screenshots attached (for UI changes)
• All your commits have a Signed-off-by line in the message. (more info)

[backstage-goalie]

Missing Changesets

The following package(s) are changed by this PR but do not have a changeset:

• @backstage-community/plugin-scaffolder-backend-module-quay

See CONTRIBUTING.md for more information about how to add changesets.

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
app	workspaces/quay/packages/app	none	v0.0.0
backend	workspaces/quay/packages/backend	none	v0.0.0
@backstage-community/plugin-scaffolder-backend-module-quay	workspaces/quay/plugins/quay-actions	none	v2.16.0
@backstage-community/plugin-quay-backend	workspaces/quay/plugins/quay-backend	patch	v1.12.0
@backstage-community/plugin-quay-common	workspaces/quay/plugins/quay-common	patch	v1.17.0
@backstage-community/plugin-quay	workspaces/quay/plugins/quay	patch	v1.30.0