Fix: Contextual menu label missing overflow hidden (microsoft#26591)

* fix: ContextualMenu label was missing overflow hidden

* change file

* snaps

Author: micahgodbolt

change/@fluentui-react-0437e436-ce0b-49ed-b3a5-5b0478c2db87.json

@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "fix: ContextualMenu label was missing overflow hidden",
+  "packageName": "@fluentui/react",
+  "email": "mgodbolt@microsoft.com",
+  "dependentChangeType": "patch"
+}

packages/react/src/components/ContextualMenu/ContextualMenu.cnstyles.ts

@@ -141,6 +141,7 @@ export const getMenuItemStyles = memoizeFunction(
         flexGrow: '1',
         textOverflow: 'ellipsis',
         whiteSpace: 'nowrap',
+        overflow: 'hidden',
       },
       secondaryText: {
         color: theme.palette.neutralSecondary,

packages/react/src/components/ContextualMenu/__snapshots__/ContextualMenu.test.tsx.snap

@@ -427,6 +427,7 @@ exports[`ContextualMenu ContextualMenu snapshot ContextualMenu should be present
                                   margin-left: 4px;
                                   margin-right: 4px;
                                   margin-top: 0;
+                                  overflow: hidden;
                                   text-overflow: ellipsis;
                                   vertical-align: middle;
                                   white-space: nowrap;