Update release notes for v25.3-v25.3.6

Author: Automated Release Bot

src/current/_data/releases.yml

@@ -10013,6 +10013,34 @@
   previous_release: v25.4.0
 
 
+- release_name: v26.1.0-alpha.2
+  major_version: v26.1
+  release_date: '2025-12-11'
+  release_type: Testing
+  go_version: go1.25.3
+  sha: 7991c17b6f2957e381666bf13d6405c8037f46c1
+  has_sql_only: true
+  has_sha256sum: true
+  mac:
+    mac_arm: true
+    mac_arm_experimental: true
+    mac_arm_limited_access: false
+  windows: true
+  linux:
+    linux_arm: true
+    linux_arm_experimental: false
+    linux_arm_limited_access: false
+    linux_intel_fips: true
+    linux_arm_fips: false
+  docker:
+    docker_image: cockroachdb/cockroach-unstable
+    docker_arm: true
+    docker_arm_experimental: false
+    docker_arm_limited_access: false
+  source: true
+  previous_release: v26.1.0-alpha.1
+
+
 - release_name: v25.3.6
   major_version: v25.3
   release_date: '2025-12-12'