feat: use Git notes to store the channels on which a version has been released

BREAKING CHANGE: this feature change the way semantic-release keep track of the channels on which a version has been released.
It now use a JSON object stored in a [Git note](https://git-scm.com/docs/git-notes) instead of Git tags formatted as v{version}@{channel}.

The tags formatted as v{version}@{channel} will now be ignored. If you have made releases with v16.0.0 on branches other than the default one you will have to update your repository.

The changes to make consist in:
- Finding all the versions that have been released on a branch other than the default one by searching for all tags formatted v{version}@{channel}
- For each of those version:
  - Create a tag without the {@channel} if none doesn't already exists
  - Add a Git note to the tag without the {@channel} containing the channels on which the version was released formatted as `{"channels":["channel1","channel2"]}` and using `null` for the default channel (for example.`{"channels":[null,"channel1","channel2"]}`)
  - Push the tags and notes
  - Update the GitHub releases that refer to a tag formatted as v{version}@{channel} to use the tag without it
  - Delete the tags formatted as v{version}@{channel}

index.js

@@ -17,7 +17,7 @@ const {extractErrors, makeTag} = require('./lib/utils');
 const getGitAuthUrl = require('./lib/get-git-auth-url');
 const getBranches = require('./lib/branches');
 const getLogger = require('./lib/get-logger');
-const {verifyAuth, isBranchUpToDate, getGitHead, tag, push, getTagHead} = require('./lib/git');
+const {verifyAuth, isBranchUpToDate, getGitHead, tag, push, pushNotes, getTagHead, addNote} = require('./lib/git');
 const getError = require('./lib/get-error');
 const {COMMIT_NAME, COMMIT_EMAIL} = require('./lib/definitions/constants');
 
@@ -109,9 +109,10 @@ async function run(context, plugins) {
       if (options.dryRun) {
         logger.warn(`Skip ${nextRelease.gitTag} tag creation in dry-run mode`);
       } else {
-        await tag(nextRelease.gitTag, nextRelease.gitHead, {cwd, env});
+        await addNote({channels: [...currentRelease.channels, nextRelease.channel]}, nextRelease.gitHead, {cwd, env});
         await push(options.repositoryUrl, {cwd, env});
-        logger.success(`Created tag ${nextRelease.gitTag}`);
+        await pushNotes(options.repositoryUrl, {cwd, env});
+        logger.success(`Add channel ${nextRelease.channel} to tag ${nextRelease.gitTag}`);
       }
 
       context.branch.tags.push({
@@ -148,7 +149,7 @@ async function run(context, plugins) {
 
   const nextRelease = {
     type: await plugins.analyzeCommits(context),
-    channel: context.branch.channel,
+    channel: context.branch.channel || null,
     gitHead: await getGitHead({cwd, env}),
   };
   if (!nextRelease.type) {
@@ -158,8 +159,8 @@ async function run(context, plugins) {
 
   context.nextRelease = nextRelease;
   nextRelease.version = getNextVersion(context);
-  nextRelease.gitTag = makeTag(options.tagFormat, nextRelease.version, nextRelease.channel);
-  nextRelease.name = makeTag(options.tagFormat, nextRelease.version);
+  nextRelease.gitTag = makeTag(options.tagFormat, nextRelease.version);
+  nextRelease.name = nextRelease.gitTag;
 
   if (context.branch.type !== 'prerelease' && !semver.satisfies(nextRelease.version, context.branch.range)) {
     throw getError('EINVALIDNEXTVERSION', {
@@ -181,7 +182,9 @@ async function run(context, plugins) {
   } else {
     // Create the tag before calling the publish plugins as some require the tag to exists
     await tag(nextRelease.gitTag, nextRelease.gitHead, {cwd, env});
+    await addNote({channels: [nextRelease.channel]}, nextRelease.gitHead, {cwd, env});
     await push(options.repositoryUrl, {cwd, env});
+    await pushNotes(options.repositoryUrl, {cwd, env});
     logger.success(`Created tag ${nextRelease.gitTag}`);
   }