feat: left-align the hide/show environments button

Aligns the button to the start of its container.

[DX-4921](https://linear.app/unleash/issue/DX-4921/left-align-the-hideshow-environments-dropdown)

**Before**
<img width="389" height="588" alt="image"
src="https://github.com/user-attachments/assets/1f371340-7d7c-487d-bec4-b9333f069d71"
/>

**After**
<img width="373" height="593" alt="image"
src="https://github.com/user-attachments/assets/e45f90d4-4874-436b-b06f-5b004915fe29"
/>

frontend/src/component/feature/FeatureView/FeatureOverview/FeatureOverviewMetaData/EnvironmentVisibilityMenu/EnvironmentVisibilityMenu.tsx

@@ -17,7 +17,7 @@ const menuId = 'environment-visibility-menu';
 
 const StyledContainer = styled('div')(({ theme }) => ({
     display: 'flex',
-    justifyContent: 'center',
+    justifyContent: 'flex-start',
     paddingTop: theme.spacing(4),
 }));