Add known issue for HA GitHub Actions settings to GHES 3.18.8, 3.19.5, and 3.20.1 release notes (#60879)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: pallsama <96553709+pallsama@users.noreply.github.com>

Author: Copilot

data/release-notes/enterprise-server/3-18/8.yml

@@ -71,6 +71,8 @@ sections:
     - |
       To improve page load performance, user profile pages display a maximum of 24 organizations. When viewing your own profile, a "View all" link provides access to the full list in organization settings. When viewing another user's profile, a count displays any additional organizations beyond the first 24.
   known_issues:
+    - |
+      On instances configured for high availability, you will not be able to change GitHub Actions settings through the Management Console. Other settings are not affected. [Updated: 2026-04-22]
     - |
       First time setups of GitHub Actions with OpenID Connect (OIDC) fail with an error on the `Update Servicing Resources` step. This problem does not affect instances where GitHub Actions is already enabled.
 

data/release-notes/enterprise-server/3-19/5.yml

@@ -83,6 +83,8 @@ sections:
     - |
       To improve page load performance, user profile pages display a maximum of 24 organizations. When viewing your own profile, a "View all" link provides access to the full list in organization settings. When viewing another user's profile, a count displays any additional organizations beyond the first 24.
   known_issues:
+    - |
+      On instances configured for high availability, you will not be able to change GitHub Actions settings through the Management Console. Other settings are not affected. [Updated: 2026-04-22]
     - |
       First time setups of GitHub Actions with OpenID Connect (OIDC) fail with an error on the `Update Servicing Resources` step. This problem does not affect instances where GitHub Actions is already enabled.
 

data/release-notes/enterprise-server/3-20/1.yml

@@ -83,6 +83,8 @@ sections:
     - |
       To improve page load performance, user profile pages display a maximum of 24 organizations. When viewing your own profile, a "View all" link provides access to the full list in organization settings. When viewing another users profile, a count displays any additional organizations beyond the first 24.
   known_issues:
+    - |
+      On instances configured for high availability, you will not be able to change GitHub Actions settings through the Management Console. Other settings are not affected. [Updated: 2026-04-22]
     - |
       First time setups of GitHub Actions with OpenID Connect (OIDC) fail with an error on the `Update Servicing Resources` step. This problem does not affect instances where GitHub Actions is already enabled.