Revert "Finalize v2023.1 release (#5062)" (#5064)

This reverts commit 0fc5526f2b01a0cc89192c10cf8bef77f1007a62.

CHANGES

diff --git a/CHANGES b/CHANGES
index f24da41..39a878c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,9 +1,6 @@
 Revision history for SPIRV-Tools
 
-v2023.2-dev 2023-01-17
-   - Start v2023.2-dev
-
-v2023.1 2023-01-17
+v2023.1-dev 2023-01-13
   - General
     - Renamed "master" to "main" (issue#5051)
     - Validate version 5 of clspv reflection (#5050)