Update release notes for v26.1-v26.1.0-alpha.1

Author: Automated Release Bot

src/current/_data/releases.yml

@@ -9956,3 +9956,30 @@
     docker_arm_limited_access: false
   source: true
   previous_release: v24.3.22
+
+
+- release_name: v26.1.0-alpha.1
+  major_version: v26.1
+  release_date: '2025-12-03'
+  release_type: Testing
+  go_version: go1.25.3
+  sha: d90b48fdc3077318799afd2939837c79289156f4
+  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