Update RHEL requirements to include GLIBC >=2.34, remove Go/kernel version mentions

- Updated minimum RHEL requirements to specify GLIBC >=2.34 instead of Go 1.24/kernel 3.2+ references
- Added RHEL9+/GLIBC requirements to important upgrade notes for v10.10
- Removed inaccurate Go version and kernel version mentions as requested

Co-authored-by: Sven Hüster <svelle@users.noreply.github.com>

Author: claude[bot]

source/deploy/software-hardware-requirements.rst

@@ -89,7 +89,7 @@ Mattermost server operating system
 
 .. important::
 
-    Starting with Mattermost v10.10, the minimum supported RedHat Enterprise Linux version is RHEL9 due to the upgrade to Go 1.24, which requires Linux kernel 3.2 or later. Customers running RHEL8 or earlier should upgrade to RHEL9 or later before upgrading to Mattermost v10.10 or later. Note that Extended Update Support for RHEL8 ended on May 31, 2025.
+    Starting with Mattermost v10.10, the minimum supported RedHat Enterprise Linux version is RHEL9 due to GLIBC version requirements (GLIBC >=2.34). Customers running RHEL8 or earlier should upgrade to RHEL9 or later before upgrading to Mattermost v10.10 or later. Note that Extended Update Support for RHEL8 ended on May 31, 2025.
 
 While community support exists for Fedora, FreeBSD, and Arch Linux, Mattermost does not currently include production support for these platforms.
 

source/upgrade/important-upgrade-notes.rst

@@ -53,6 +53,10 @@ We recommend reviewing the `additional upgrade notes <#additional-upgrade-notes>
 |                                                    |                                                                                                                                                                  |
 |                                                    | MySQL: https://github.com/mattermost/mattermost/blob/master/server/channels/db/migrations/mysql/000139_remoteclusters_add_last_global_user_sync_at.down.sql      |
 |                                                    | and https://github.com/mattermost/mattermost/blob/master/server/channels/db/migrations/mysql/000139_remoteclusters_add_last_global_user_sync_at.up.sql           |
+|                                                    +------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+|                                                    | Starting with Mattermost v10.10, the minimum supported RedHat Enterprise Linux version is RHEL9 due to GLIBC version requirements (GLIBC >=2.34). Customers    |
+|                                                    | running RHEL8 or earlier should upgrade to RHEL9 or later before upgrading to Mattermost v10.10 or later. Note that Extended Update Support for RHEL8 ended on |
+|                                                    | May 31, 2025.                                                                                                                                                    |
 +----------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 | v10.9                                              | A new index to the ``CategoryId`` column in ``SidebarChannels`` table was added to improve query performance. No database downtime is expected for this upgrade. |
 |                                                    | For PostgreSQL, it takes around 2s to add the index on a table with 1.2M rows with an instance size of 8 cores and 16GB RAM. For MySQL, it takes around 5s on a  |