feat: remove RENOVATE_LEGACY_GIT_AUTHOR_EMAIL (#9389)

Removes RENOVATE_LEGACY_GIT_AUTHOR_EMAIL support. 

Closes #9111

BREAKING CHANGE: RENOVATE_LEGACY_GIT_AUTHOR_EMAIL is no longer supported. Use `ignoredAuthors` in config instead.

docs/usage/self-hosted-experimental.md

@@ -27,11 +27,6 @@ If set to any integer, Renovate will use this integer instead of the default npm
 If set to any value, Renovate will skip its default artifacts filter check in the Maven datasource.
 Skiping the check will speed things up, but may result in versions being returned which don't properly exist on the server.
 
-## RENOVATE_LEGACY_GIT_AUTHOR_EMAIL
-
-An additional `gitAuthor` email to ignore.
-This variable is deprecated: use `ignoredAuthors` instead.
-
 ## RENOVATE_PAGINATE_ALL
 
 If set to any value, Renovate will always paginate requests to GitHub fully, instead of stopping after 10 pages.

lib/util/git/index.ts

@@ -488,7 +488,6 @@ export async function isBranchModified(branchName: string): Promise<boolean> {
   ).trim();
   const { gitAuthorEmail } = config;
   if (
-    lastAuthor === process.env.RENOVATE_LEGACY_GIT_AUTHOR_EMAIL || // remove in next major release
     lastAuthor === gitAuthorEmail ||
     config.ignoredAuthors.some((ignoredAuthor) => lastAuthor === ignoredAuthor)
   ) {