Revert "Prepare release v2025.1 (#6011)"

This reverts commit 132103f44d719f8df456c4c7b2658278dc422dc6.
diff --git a/CHANGES b/CHANGES
index 1aad4d3..007e901 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,40 +1,5 @@
 Revision history for SPIRV-Tools
 
-v2025.1 2025-02-28
-  - General
-    - diff: Fix crash in OpString matching (#5988)
-    - Add SPV_AMDX_shader_enqueue version 2 support (#5838)
-    - add support for SPV_INTEL_subgroup_matrix_multiply_accumulate (#5928)
-    - update cmake_minimum_required to 3.22.1 (#5925)
-    - Add OpImageSampleFootprintNV to IsAllowedSampledImageOperand (#5914)
-    - assembler: ensure progress when seeking the version string (#5910)
-  - Optimizer
-    - opt: keep all OpSource instructions (#5901)
-    - [opt] Fix bug opt::InstructionBuilder::AddVariable (#6007)
-    - [OPT] Add SPV_KHR_ray_tracing to allow list (#5941)
-    - opt: keep all OpSource instructions (#5901)
-  - Validator
-    - spirv-val: Add AllowVulkan32BitBitwise option (#6001)
-    - Fix untyped pointer comparison validation (#6004)
-    - spirv-val: Update VUIDs for 308 header (#5990)
-    - spirv-val: fix env parsing for vk1.1spv1.4 (#5985)
-    - Add validation for SPV_NV_linear_swept_spheres. (#5975)
-    - Add validation SPV_NV_cluster_acceleration_structure. (#5974)
-    - Improve the instruction diagnostic for some access chain errors (#5978)
-    - Update physical storage buffer validation to match SPIR-V 1.6.5 (#5977)
-    - Validate SPV_NV_cooperative_vector (#5972)
-    - Fix layout checks with untyped pointers (#5970)
-    - spirv-val: Update mislabeled VUIDs (#5964)
-    - More explicit layout validation (#5958)
-    - spirv-val: Add VK_KHR_maintenance8 support (#5951)
-    - Add EXT_mesh_shader validation support (#5640)
-    - spirv-val: Remove OpenCL ivec3 req (#5940)
-    - spirv-val: Validate zero product workgroup size (#5407)
-    - Relax DebugLine validation (#5916)
-  - Linker
-    - linker: remove LinkOnceODR decorations when linking executables (#5979)
-    - fix: handle LinkOnceODR correctly (#5938)
-
 v2024.4 2024-12-04
   - General
     - Add FPEncoding operand type. (#5726)