Upgrade to Mattermost 10.11

[gsanchietti]

Current Mattermost version is 10.5.14 and it's now EOL.

Upgrade to latest 10.11.x release:
https://docs.mattermost.com/product-overview/mattermost-v10-changelog.html#release-v10-11-extended-support-release

The 10.11 release will be EOL on 08/2026

[DavidePrincipi]

In Testing 2.4.0-dev.1

Test case

The Testing version upgrades from old 10.5 ESR to current 10.11 ESR. Upstream claims it is fully tested and supported.

• Test the update of a production system from 2.3.0 (our latest stable, on 10.5.14)
• Test the update of a system from 2.2.0 (first 10.5 line, on 10.5.2)

Note

• Migration tool goes to 2.0.7, which is on MM 8
• Versions 2.0.8-2.1.1 is on MM 9

[DavidePrincipi]

Test the update of a production system from 2.3.0 (our latest stable, on 10.5.14)

VERIFIED

[DavidePrincipi]

Test the update of a system from 2.2.0 (first 10.5 line, on 10.5.2)

VERIFIED