♿️(Modal) remove tabindex from content modal

The screen reader was reading the content of the
modal as a focusable element, but the content of
the modal is not interactive.
This change removes the tabindex from the content
modal in the Modal component.

packages/react/CHANGELOG.md

@@ -1,5 +1,11 @@
 # @gouvfr-lasuite/cunningham-react
 
+## [unreleased]
+
+### Minor Changes
+
+- ♿️(Modal) remove tabindex from content modal
+
 ## 4.2.0
 
 ### Minor Changes