chore: prepare releases notes (#640)

<!-- markdownlint-disable MD041 -->
#### What this PR does / why we need it
update release notes again

#### Which issue(s) this PR fixes
<!--
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
-->

Author: fabianburth

docs/release_notes/v0.26.0.md

@@ -1,5 +1,7 @@
 # Release v0.26.0
 
+- chore: upgrade release runner to avoid action failures (#639)
+- chore: prepare release for version v0.26.0 (#638)
 - chore: upgrade ocm version (#635)
 - chore: upgrade to ocm version 0.14.0 (after restructure) (#632)
 - chore: upgrade ocm (#630)