Bump the all-npm-dependencies group across 2 directories with 2 updates (#516)

Bumps the all-npm-dependencies group with 2 updates in the / directory:
[@sap/cds-dk](https://cap.cloud.sap/) and @sap/xssec.
Bumps the all-npm-dependencies group with 1 update in the /mtx/sidecar
directory: @sap/xssec.

Updates `@sap/cds-dk` from 9.1.0 to 9.1.1

Updates `@sap/xssec` from 4.8.0 to 4.9.0

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]