switch @types/jest to only be depended on by @backstage/cli

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/techdocs/package.json

@@ -75,7 +75,6 @@
     "@testing-library/user-event": "^14.0.0",
     "@types/dompurify": "^2.2.2",
     "@types/event-source-polyfill": "^1.0.0",
-    "@types/jest": "^26.0.7",
     "@types/node": "^16.11.26",
     "canvas": "^2.6.1",
     "cross-fetch": "^3.1.5",