Move MIEQ to composite index tests (#12416)

Author: milaGGL

Firestore/CHANGELOG.md

@@ -1,3 +1,6 @@
+# Unreleased
+- [feature] Enable queries with range & inequality filters on multiple fields. (#12416)
+
 # 10.23.0
 - [feature] Enable snapshot listener option to retrieve data from local cache only. (#12370)
 - [fixed] Update gRPC dependency to 1.62.* (#12098, #12021)