Add a checklist item for updating internal package versions (realm#4666)

.github/pull_request_template.md

@@ -11,6 +11,7 @@ This closes # ??? <!-- link to an existing issue -->
 * [ ] 📝 `Compatibility` label is updated or copied from previous entry
 * [ ] 🚦 Tests
 * [ ] 🔀 Executed flexible sync tests locally if modifying flexible sync
+* [ ] 📦 Updated internal package version in consuming `package.json`s (if updating internal packages)
 * [ ] 📱 Check the React Native/other sample apps work if necessary
 * [ ] 📝 Public documentation PR created or is not necessary
 * [ ] 💥 `Breaking` label has been applied or is not necessary