Recording 4.1.9.0mixed mode test results in release notes

Author: foundationdb-ci

docs/sphinx/source/ReleaseNotes.md

@@ -70,7 +70,13 @@ Users performing online updates are encouraged to update from [4.0.559.4](#40559
 
 **[Full Changelog (4.1.8.0...4.1.9.0)](https://github.com/FoundationDB/fdb-record-layer/compare/4.1.8.0...4.1.9.0)**
 
-<!-- MIXED_MODE_RESULTS 4.1.9.0 PLACEHOLDER -->
+#### Mixed Mode Test Results
+
+Mixed mode testing run against the following previous versions:
+
+❌`4.0.559.1`, ❌`4.0.559.2`, ❌`4.0.559.3`, ✅`4.0.559.4`, ✅`4.0.559.6`, ❌`4.0.561.0`, ❌`4.0.562.0`, ❌`4.0.564.0`, ❌`4.0.565.0`, ❌`4.0.566.0`, ❌`4.0.567.0`, ❌`4.0.568.0`, ❌`4.0.569.0`, ❌`4.0.570.0`, ❌`4.0.571.0`, ❌`4.0.572.0`, ❌`4.0.573.0`, ❌`4.0.574.0`, ❌`4.0.575.0`, ❌`4.1.4.0`, ✅`4.1.5.0`, ✅`4.1.6.0`, ✅`4.1.8.0`
+
+[See full test run](https://github.com/FoundationDB/fdb-record-layer/actions/runs/13729472581)
 
 
 ### 4.1.8.0