Fix name of new flag in changelog (#14437)

Author: bdukes

packages/astro/CHANGELOG.md

@@ -50,7 +50,7 @@
 
   Previously, when two dynamic routes `/[foo]` and `/[bar]` returned values on their `getStaticPaths` that resulted in the same final path, only one of the routes would be rendered while the other would be silently ignored. Now, when this happens, a warning will be displayed explaining which routes collided and on which path.
 
-  Additionally, a new experimental flag `failOnPrerenderCollision` can be used to fail the build when such a collision occurs.
+  Additionally, a new experimental flag `failOnPrerenderConflict` can be used to fail the build when such a collision occurs.
 
 ### Patch Changes