do not migrate group-[]:flex to in-[.group]:flex

Because this requires prefixing the `.group` if the prefix is
configured.

packages/@tailwindcss-upgrade/src/template/codemods/modernize-arbitrary-values.test.ts

@@ -19,16 +19,6 @@ test.each([
   ['[p_&]:flex', 'in-[p]:flex'],
   ['[.foo_&]:flex', 'in-[.foo]:flex'],
   ['[[data-visible]_&]:flex', 'in-data-visible:flex'],
-  // Some extreme examples of what happens in the wild:
-  ['group-[]:flex', 'in-[.group]:flex'],
-  ['group-[]/name:flex', 'in-[.group\\/name]:flex'],
-
-  // These shouldn't happen in the real world (because compound variants are
-  // new). But this could happen once we allow codemods to run in v4+ projects.
-  ['has-group-[]:flex', 'has-in-[.group]:flex'],
-  ['has-group-[]/name:flex', 'has-in-[.group\\/name]:flex'],
-  ['not-group-[]:flex', 'not-in-[.group]:flex'],
-  ['not-group-[]/name:flex', 'not-in-[.group\\/name]:flex'],
 
   // nth-child
   ['[&:nth-child(2)]:flex', 'nth-2:flex'],

packages/@tailwindcss-upgrade/src/template/codemods/modernize-arbitrary-values.ts

@@ -28,31 +28,6 @@ export function modernizeArbitraryValues(
         }
       }
 
-      // Promote `group-[]:flex` to `in-[.group]:flex`
-      //                ^^ Yes, this is empty
-      // Promote `group-[]/name:flex` to `in-[.group\/name]:flex`
-      if (
-        variant.kind === 'compound' &&
-        variant.root === 'group' &&
-        variant.variant.kind === 'arbitrary' &&
-        variant.variant.selector === '&:is()'
-      ) {
-        // `group-[]`
-        if (variant.modifier === null) {
-          changed = true
-          Object.assign(variant, designSystem.parseVariant('in-[.group]'))
-        }
-
-        // `group-[]/name`
-        else if (variant.modifier.kind === 'named') {
-          changed = true
-          Object.assign(
-            variant,
-            designSystem.parseVariant(`in-[.group\\/${variant.modifier.value}]`),
-          )
-        }
-      }
-
       // Expecting an arbitrary variant
       if (variant.kind !== 'arbitrary') continue