Fix CI badges in README.md

Signed-off-by: Florian Vahl <[email protected]>

README.md

@@ -1,7 +1,7 @@
 # RQT Image Overlay
 
 [![Build and Test (humble)](../../actions/workflows/build_and_test_humble.yaml/badge.svg?branch=humble)](../../actions/workflows/build_and_test_humble.yaml?query=branch:humble)
-[![Build and Test (iron)](../../actions/workflows/build_and_test_iron.yaml/badge.svg?branch=rolling)](../../actions/workflows/build_and_test_iron.yaml?query=branch:rolling)
+[![Build and Test (jazzy)](../../actions/workflows/build_and_test_jazzy.yaml/badge.svg?branch=jazzy)](../../actions/workflows/build_and_test_jazzy.yaml?query=branch:jazzy)
 [![Build and Test (rolling)](../../actions/workflows/build_and_test_rolling.yaml/badge.svg?branch=rolling)](../../actions/workflows/build_and_test_rolling.yaml?query=branch:rolling)
 
 For more information, see our [Documentation](https://rqt-image-overlay.readthedocs.io/en/latest/index.html).