fix(graphql): invalid enum names when values include brackets (#13597)

### What?

Brackets (`[ ]`) in option values end up in GraphQL enum names via
`formatName`, causing schema generation to fail. This PR adds a single
rule to `formatName`:

- replace `[` and `]` with `_`

### Why?

Using `_` (instead of removing the brackets) is safer and more
consistent:

- Avoid collisions: removal can merge distinct strings (`"A[B]"` →
`"AB"`). `_` keeps them distinct (`"A_B"`).
- **Consistency**: `formatName` already maps punctuation to `_` (`. - /
+ , ( ) '`). Brackets follow the same rule.

Readability: `mb-[150px]` → `mb__150px_` is clearer than `mb150px`.

Digits/units safety: removal can jam characters (`w-[2/3]` → `w23`); `_`
avoids that (`w_2_3_`).

### How?

Update formatName to include a bracket replacement step:

```
.replace(/\[|\]/g, '_')
```

No other call sites or value semantics change; only names containing
brackets are affected.

Fixes #13466 


---
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used, see below:
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packages/graphql/src/utilities/formatName.ts

@@ -22,6 +22,7 @@ export const formatName = (string: string): string => {
     .replace(/\)/g, '_')
     .replace(/'/g, '_')
     .replace(/ /g, '')
+    .replace(/\[|\]/g, '_')
 
   return formatted || '_'
 }

test/graphql-schema-gen/config.ts

@@ -145,6 +145,23 @@ export default buildConfigWithDefaults({
             },
           ],
         },
+        {
+          name: 'some[text]',
+          type: 'text',
+        },
+        {
+          name: 'spaceBottom',
+          type: 'select',
+          required: false,
+          defaultValue: 'mb-0',
+          options: [
+            { label: 'None', value: 'mb-0' },
+            { label: 'Small', value: 'mb-8' },
+            { label: 'Medium', value: 'mb-16' },
+            { label: 'Large', value: 'mb-24' },
+            { label: 'Extra Large', value: 'mb-[150px]' },
+          ],
+        },
       ],
     },
     {