Make MUIv4 not optional

- Fix smaller v5 errors in GraphQL Plugin

Signed-off-by: Philipp Hugenroth <philipph@spotify.com>

plugins/graphiql/package.json

@@ -37,7 +37,7 @@
     "@backstage/theme": "workspace:^",
     "@mui/icons-material": "^5.11.0",
     "@mui/lab": "5.0.0-alpha.114",
-    "@mui/material": "^5.11.2",
+    "@mui/material": "^5.12.2",
     "@mui/styles": "^5.11.2",
     "graphiql": "^1.5.12",
     "graphql": "^16.0.0",

plugins/graphiql/src/components/GraphiQLBrowser/GraphiQLBrowser.tsx

@@ -69,15 +69,11 @@ export const GraphiQLBrowser = (props: GraphiQLBrowserProps) => {
           classes={{ root: classes.tabs }}
           value={tabIndex}
           onChange={(_, value) => setTabIndex(value)}
+          indicatorColor="secondary"
           textColor="inherit"
         >
           {endpoints.map(({ title }, index) => (
-            <Tab
-              key={index}
-              label={title}
-              value={index}
-              sx={{ color: 'inherit' }}
-            />
+            <Tab key={index} label={title} sx={{ color: 'inherit' }} />
           ))}
         </Tabs>
         <Divider />