CXX-3002 update release notes to account for new branch protection rules (#1385)

Author: eramongodb

etc/releasing.md

@@ -193,6 +193,12 @@ Verify there are no unexpected errors or issues.
 
 ## Release Steps
 
+### Branch Protection Rules
+
+The release process may require creating new branches, new tags, and directly pushing to development branches. These operations are normally restricted by branch protection rules.
+
+When assigned the responsibility of performing a release, submit a request to a repository administrator to be temporarily added to the [dbx-c-cxx-releases](https://github.com/orgs/mongodb/teams/dbx-c-cxx-releases/) team for the duration of the release process. The team member must be added via [MANA](https://mana.corp.mongodb.com/resources/68029673d39aa9f7de6399f9) (the GitHub team is usually empty; no member has the maintainer role).
+
 ### Update CHANGELOG...
 
 This step depends on the release type.
@@ -848,6 +854,12 @@ The C++ Driver Team
 
 Add an entry to the [C/C++ Release Info](https://docs.google.com/spreadsheets/d/1yHfGmDnbA5-Qt8FX4tKWC5xk9AhzYZx1SKF4AD36ecY) spreadsheet documenting the date, release version, author (of the release), and additional comments.
 
+### Update Branch Protection Rules
+
+Notify a repository administrator that the previous stable release branch (which will no longer recieve any further updates) may now be "locked" by adding it to the list of branches in the "Restrict Branch Updates" ruleset.
+
+Once the release process is complete, use [MANA](https://mana.corp.mongodb.com/resources/68029673d39aa9f7de6399f9) to remove yourself from the [dbx-c-cxx-releases](https://github.com/orgs/mongodb/teams/dbx-c-cxx-releases/) team or request a repository administrator to remove you instead.
+
 ## Packaging
 
 ### vcpkg