deps [nfc]: Add metro-babel-register to direct dev-deps

At present, we get this indirectly through [email protected], which is
pulled in via RN.

In RN v0.68, we'll get [email protected], and that drops this dependency.
But we still need it -- without it, RN's `jest/preprocessor.js` fails,
breaking our Jest tests.  So add it in directly.

Author: gnprice

package.json

@@ -117,6 +117,7 @@
     "jest-expo": "^45.0.0",
     "jest-extended": "^3.2.0",
     "jetifier": "^2.0.0",
+    "metro-babel-register": "^0.66.2",
     "metro-react-native-babel-preset": "^0.66.2",
     "prettier": "^2.6.2",
     "prettier-eslint": "^15.0.0",

yarn.lock

@@ -8516,7 +8516,7 @@ messageformat@^2.2.1:
     messageformat-formatters "^2.0.1"
     messageformat-parser "^4.1.2"
 
-[email protected]:
+[email protected], metro-babel-register@^0.66.2:
   version "0.66.2"
   resolved "https://registry.yarnpkg.com/metro-babel-register/-/metro-babel-register-0.66.2.tgz#c6bbe36c7a77590687ccd74b425dc020d17d05af"
   integrity sha512-3F+vsVubUPJYKfVMeol8/7pd8CC287Rw92QYzJD8LEmI980xcgwMUEVBZ0UIAUwlLgiJG/f4Mwhuji2EeBXrPg==