test(ssr-compiler): fix style dedupe param

Author: wjhsf

packages/@lwc/engine-server/src/__tests__/fixtures/style-dedupe-with-prefix/config.json

@@ -1,4 +1,4 @@
 {
     "entry": "x/parent",
-    "styleDedupePrefix": "island1"
+    "styleDedupe": "island1"
 }

packages/@lwc/ssr-compiler/src/__tests__/fixtures.spec.ts

@@ -32,7 +32,7 @@ interface FixtureConfig {
     };
 
     /** The string used to uniquely identify one set of dedupe IDs with multiple SSR islands */
-    styleDedupePrefix?: string;
+    styleDedupe?: string;
 }
 
 vi.mock('@lwc/ssr-runtime', async () => {
@@ -127,8 +127,7 @@ describe.concurrent('fixtures', () => {
                         'fixture-test',
                         module,
                         config?.props ?? {},
-                        config?.styleDedupePrefix ?? '',
-                        true,
+                        config?.styleDedupe ?? true,
                         SSR_MODE
                     )
                 );