package.json: Change repo URL to `git+https`. (#24305)

package.json

@@ -67,7 +67,7 @@
   "main": "dist/js/bootstrap",
   "repository": {
     "type": "git",
-    "url": "https://github.com/twbs/bootstrap.git"
+    "url": "git+https://github.com/twbs/bootstrap.git"
   },
   "bugs": {
     "url": "https://github.com/twbs/bootstrap/issues"