Change code owners for 6.2 to branch managers

Author: ahoppen

.github/CODEOWNERS

@@ -1,25 +1,2 @@
-# This file is a list of the people responsible for ensuring that patches for a
-# particular part of SwiftSyntax are reviewed, either by themselves or by
-# someone else. They are also the gatekeepers for their part of Swift, with the
-# final word on what goes in or not.
-
-# Lines starting with '#' are comments.
-# Each line is a file pattern followed by one or more owners.
-# Order is important. The last matching pattern has the most precedence.
-
-# Owner of anything in SwiftSyntax not owned by anyone else.
-* @ahoppen @bnbarham
-
-# Macros
-/Sources/SwiftSyntaxMacros @DougGregor
-/Tests/SwiftSyntaxMacrosTest @DougGregor
-
-# SwiftOperators
-/Sources/SwiftOperators @DougGregor
-/Tests/SwiftOperatorsTest @DougGregor
-
-/utils/bazel @keith
-*.bazel @keith
-WORKSPACE @keith
-.bazelrc @keith
-.bazelversion @keith
+# For the release branch @swiftlang/swift-branch-managers needs to approve the changes
+* @swiftlang/swift-branch-managers