Merge pull request #82 from stackhpc/upstream/master-2025-08-18

Synchronise master with upstream

Author: priteau

doc/source/install/index.rst

@@ -14,14 +14,13 @@ Supported operating systems
 
 Full support (fully tested in the CI, no known or potential issues):
 
-* CentOS Stream 9
-
-  .. note::
-     RHEL 9 and derivatives are assumed to work but not tested explicitly.
-
 * Ubuntu 22.04 "Jammy" and 24.04 "Noble"
 * Debian 11 "Bullseye" and 12 "Bookworm"
 
+Deprecated support:
+
+* CentOS Stream 9
+
 .. note::
    Operating systems evolve and so does the support for them, even on stable
    branches.

releasenotes/notes/cs9deprecation-cf13061ef2b2419a.yaml

@@ -0,0 +1,7 @@
+---
+deprecations:
+  - |
+    With the upcoming support removal for Python 3.9 we can't
+    guarantee that CentOS Stream 9 jobs will keep working.
+    CentOS Stream 9 support is considered deprecated and it
+    will be removed with no further notice.