Bug 1766928 - rename release-to-esr102 migration to release-to-esr. r=gabriel

No need to keep the esr91 migration around, it already happened a year ago.

Differential Revision: https://phabricator.services.mozilla.com/D147087

taskcluster/ci/config.yml

@@ -354,18 +354,6 @@ merge-automation:
             to-repo: 'https://hg.mozilla.org/releases/mozilla-release'
             to-branch: 'release'
         release-to-esr:
-            fetch-version-from: "browser/config/version.txt"
-            version-files:
-                - filename: "browser/config/version_display.txt"
-                  new-suffix: 'esr'
-            replacements: []
-            merge-old-head: false
-            base-tag: "FIREFOX_ESR_{major_version}_BASE"
-            from-repo: 'https://hg.mozilla.org/releases/mozilla-release'
-            from-branch: 'release'
-            to-repo: 'https://hg.mozilla.org/releases/mozilla-esr91'
-            to-branch: 'esr91'
-        release-to-esr102:
             fetch-version-from: "browser/config/version.txt"
             version-files:
                 - filename: "browser/config/version_display.txt"