OWNERS(CHANGELOG): Move reviewers/approvers to CHANGELOG/ dir

Given we're pulling the relnotes team into review, the changes to
reviewers will happen a little more frequently, which means we'll have
the same issue of needing a top-level approver to do updates that we
were trying to avoid by creating the subdirectory in the first place.

Signed-off-by: Stephen Augustus <foo@auggie.dev>

CHANGELOG/OWNERS

@@ -1,9 +1,21 @@
 # See the OWNERS docs at https://go.k8s.io/owners
 
 approvers:
-  - changelog-approvers
+  - wilsonehusin # 1.21 Release Notes Lead
+  - cpanato # Release Manager
+  - feiskyer # Release Manager
+  - hasheddan # Release Manager / SIG Technical Lead
+  - idealhack # Release Manager
+  - justaugustus # Release Manager / SIG Chair
+  - puerco # Release Manager
+  - saschagrunert # Release Manager / SIG Chair
+  - xmudrii # Release Manager
 reviewers:
-  - changelog-reviewers
+  - wilsonehusin # 1.21 Release Notes Lead
+  - ashnehete # 1.21 Release Notes shadow
+  - melodychn # 1.21 Release Notes shadow
+  - pmmalinov01 # 1.21 Release Notes shadow
+  - soniasingla # 1.21 Release Notes shadow
 
 labels:
   - sig/release

OWNERS_ALIASES

@@ -153,22 +153,6 @@ aliases:
     - puerco # Release Manager
     - saschagrunert # Release Manager / SIG Chair
     - xmudrii # Release Manager
-  changelog-approvers:
-    - wilsonehusin # 1.21 Release Notes Lead
-    - cpanato # Release Manager
-    - feiskyer # Release Manager
-    - hasheddan # Release Manager / SIG Technical Lead
-    - idealhack # Release Manager
-    - justaugustus # Release Manager / SIG Chair
-    - puerco # Release Manager
-    - saschagrunert # Release Manager / SIG Chair
-    - xmudrii # Release Manager
-  changelog-reviewers:
-    - wilsonehusin # 1.21 Release Notes Lead
-    - ashnehete # 1.21 Release Notes shadow
-    - melodychn # 1.21 Release Notes shadow
-    - pmmalinov01 # 1.21 Release Notes shadow
-    - soniasingla # 1.21 Release Notes shadow
 
   sig-storage-approvers:
     - saad-ali