Allow ActionMenu.Button alignContent prop (#202)

* Allow ActionMenu.Button alignContent prop

* changeset

Author: keithamus

.changeset/swift-lizards-vanish.md

@@ -0,0 +1,5 @@
+---
+'eslint-plugin-primer-react': patch
+---
+
+Allow ActionMenu.Button alignContent prop

src/rules/no-system-props.js

@@ -15,6 +15,7 @@ const utilityComponents = new Set(['Box', 'Text'])
 // Components for which we allow a set of prop names
 const excludedComponentProps = new Map([
   ['ActionMenu.Overlay', new Set(['width', 'height', 'maxHeight', 'position', 'top', 'right', 'bottom', 'left'])],
+  ['ActionMenu.Button', new Set(['alignContent'])],
   ['Autocomplete.Overlay', new Set(['width', 'height', 'maxHeight', 'position', 'top', 'right', 'bottom', 'left'])],
   ['AnchoredOverlay', new Set(['width', 'height'])],
   ['Avatar', new Set(['size'])],