chore: add release dates to all 2025 releases

Signed-off-by: Sergei Lukianov <[email protected]>

Author: Frostman

docs/release-notes/index.md

@@ -42,6 +42,8 @@ Date: November 20, 2025
 
 ## 25.04
 
+Date: July 31, 2025
+
 !!! note
     It's only possible to upgrade from 25.03 to 25.04 and requires all switches to run Broadcom SONiC 4.5.0.
 
@@ -73,6 +75,8 @@ Date: November 20, 2025
 
 ## 25.03
 
+Date: July 1, 2025
+
 ### Highlights
 
 - RoCE v2 (RDMA over Converged Ethernet version 2) support
@@ -104,6 +108,8 @@ Date: November 20, 2025
 
 ## 25.02
 
+Date: May 15, 2025
+
 ### Highlights
 
 - Celestica DS5000 support as a spine and limited leaf
@@ -137,6 +143,8 @@ Date: November 20, 2025
 
 ## 25.01
 
+Date: April 7, 2025
+
 ### Highlights
 
 - Broadcom SONiC 4.4.2 support (see [upgrade