fix(website): fix website aria violation (#4148)

resolves #2729


## Summary
- clean up ARIA label usage in the hamburger menu icon
- add explicit aria labels to menu toggle buttons


🚀 Preview: Add `preview` label to enable

Author: theosanderson

website/src/components/Navigation/SandwichMenu.tsx

@@ -17,7 +17,11 @@ export const SandwichMenu: FC<SandwichMenuProps> = ({ topNavigationItems, gitHub
     return (
         <div className='relative'>
             {!isOpen ? (
-                <button className='absolute z-50 bg-transparent border-none cursor-pointer' onClick={toggleMenu}>
+                <button
+                    className='absolute z-50 bg-transparent border-none cursor-pointer'
+                    onClick={toggleMenu}
+                    aria-label='Open main menu'
+                >
                     <SandwichIcon isOpen={isOpen} />
                 </button>
             ) : (
@@ -32,6 +36,7 @@ export const SandwichMenu: FC<SandwichMenuProps> = ({ topNavigationItems, gitHub
                 <button
                     className='absolute z-50 bg-transparent border-none cursor-pointer right-3 top-4'
                     onClick={toggleMenu}
+                    aria-label='Close main menu'
                 >
                     <SandwichIcon isOpen={isOpen} />
                 </button>

website/src/components/SandwichIcon.tsx

@@ -45,7 +45,7 @@ const styledHamburger = `
 
 export const SandwichIcon: FC<{ isOpen: boolean }> = ({ isOpen }) => {
     return (
-        <div className='relative' aria-label='main menu'>
+        <div className='relative'>
             <div className='hamburger'>
                 <div className={`burger bg-primary-600 burger1--${isOpen ? 'open' : 'closed'}`} />
                 <div className={`burger bg-primary-600 burger2--${isOpen ? 'open' : 'closed'}`} />