RN: Update CI & Bots to main

Summary:
Updates CI and bot configurations to use `main` instead of `master`.

I will land this after I conver the repository to `main`.

Changelog:
[Internal]

Reviewed By: JoshuaGross

Differential Revision: D29717337

fbshipit-source-id: 9aa9711df921cd7d3d94fbc3d8bb9d6e22abf5c1

.circleci/config.yml

@@ -900,7 +900,7 @@ workflows:
           filters:
             branches:
               only:
-                - master
+                - main
     jobs:
       - nightly_job
 

bots/dangerfile.js

@@ -79,17 +79,17 @@ if (!includesChangelog) {
 }
 
 // Warns if the PR is opened against stable, as commits need to be cherry picked and tagged by a release maintainer.
-// Fails if the PR is opened against anything other than `master` or `-stable`.
-const isMergeRefMaster = danger.github.pr.base.ref === 'master';
+// Fails if the PR is opened against anything other than `main` or `-stable`.
+const isMergeRefMaster = danger.github.pr.base.ref === 'main';
 const isMergeRefStable = danger.github.pr.base.ref.indexOf('-stable') !== -1;
 if (!isMergeRefMaster && isMergeRefStable) {
   const title = ':grey_question: Base Branch';
   const idea =
-    'The base branch for this PR is something other than `master`. Are you sure you want to merge these changes into a stable release? If you are interested in backporting updates to an older release, the suggested approach is to land those changes on `master` first and then cherry-pick the commits into the branch for that release. The [Releases Guide](https://github.com/facebook/react-native/blob/HEAD/Releases.md) has more information.';
+    'The base branch for this PR is something other than `main`. Are you sure you want to merge these changes into a stable release? If you are interested in backporting updates to an older release, the suggested approach is to land those changes on `main` first and then cherry-pick the commits into the branch for that release. The [Releases Guide](https://github.com/facebook/react-native/blob/HEAD/Releases.md) has more information.';
   warn(`${title} - <i>${idea}</i>`);
 } else if (!isMergeRefMaster && !isMergeRefStable) {
   const title = ':exclamation: Base Branch';
   const idea =
-    'The base branch for this PR is something other than `master`. [Are you sure you want to target something other than the `master` branch?](https://reactnative.dev/docs/contributing.html#pull-requests)';
+    'The base branch for this PR is something other than `main`. [Are you sure you want to target something other than the `main` branch?](https://reactnative.dev/docs/contributing.html#pull-requests)';
   fail(`${title} - <i>${idea}</i>`);
 }

bots/report-bundle-size.js

@@ -25,7 +25,7 @@ const datastore = require('./datastore');
 const {createOrUpdateComment} = require('./make-comment');
 
 /**
- * Generates and submits a comment. If this is run on master branch, data is
+ * Generates and submits a comment. If this is run on main branch, data is
  * committed to the store instead.
  * @param {{
       'android-hermes-arm64-v8a'?: number;
@@ -47,7 +47,7 @@ async function reportSizeStats(stats, replacePattern) {
   );
   const collection = datastore.getBinarySizesCollection(store);
 
-  if (GITHUB_REF === 'master') {
+  if (GITHUB_REF === 'main') {
     // Ensure we only store numbers greater than zero.
     const validatedStats = Object.keys(stats).reduce((validated, key) => {
       const value = stats[key];