chore(blackduck): remove unused dev dependencies

[christoph-jerolimov]

Hey, I just made a Pull Request!

The automated PR #2232 tries to update the unused dependency @types/express-serve-static-core.

This PR instead removes multiple unused devDependencies from packages/backend/package.json.

I also added a script to run yarn build:knip-reports to rebuild the knip reports.

✔️ 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-blackduck-backend
• @backstage-community/plugin-blackduck

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

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
app	workspaces/blackduck/packages/app	none	v0.0.6
backend	workspaces/blackduck/packages/backend	none	v0.0.7
@backstage-community/plugin-blackduck-backend	workspaces/blackduck/plugins/blackduck-backend	none	v0.1.0
@backstage-community/plugin-blackduck	workspaces/blackduck/plugins/blackduck	none	v0.1.0