Move typings to devDependency

Signed-off-by: Andrew Shirley <andrew.shirley@sainsburys.co.uk>
Signed-off-by: blam <ben@blam.sh>

plugins/jenkins-backend/package.json

@@ -26,7 +26,6 @@
     "@backstage/config": "^0.1.5",
     "@backstage/core": "^0.7.13",
     "@types/express": "^4.17.6",
-    "@types/jenkins": "^0.23.1",
     "cross-fetch": "^3.0.6",
     "express": "^4.17.1",
     "express-promise-router": "^4.1.0",
@@ -36,6 +35,7 @@
   },
   "devDependencies": {
     "@backstage/cli": "^0.7.0",
+    "@types/jenkins": "^0.23.1",
     "@types/supertest": "^2.0.8",
     "msw": "^0.21.2",
     "supertest": "^4.0.2"