pyproject: bump version to 0.5.0 (#3287)

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "reflex"
-version = "0.4.9"
+version = "0.5.0"
 description = "Web apps in pure Python."
 license = "Apache-2.0"
 authors = [