Remove vary: accept header as it's no longer needed

Co-authored-by: hi-ogawa <4232207+hi-ogawa@users.noreply.github.com>

Author: Copilot

packages/plugin-rsc/examples/basic/src/framework/entry.rsc.tsx

@@ -70,7 +70,6 @@ export async function handleRequest({
       status: returnValue?.ok === false ? 500 : undefined,
       headers: {
         'content-type': 'text/x-component;charset=utf-8',
-        vary: 'accept',
       },
     })
   }
@@ -93,7 +92,6 @@ export async function handleRequest({
   return new Response(htmlStream, {
     headers: {
       'content-type': 'text/html;charset=utf-8',
-      vary: 'accept',
     },
   })
 }

packages/plugin-rsc/examples/starter-cf-single/src/framework/entry.rsc.tsx

@@ -64,7 +64,6 @@ async function handler(request: Request): Promise<Response> {
       status: returnValue?.ok === false ? 500 : undefined,
       headers: {
         'content-type': 'text/x-component;charset=utf-8',
-        vary: 'accept',
       },
     })
   }
@@ -83,7 +82,6 @@ async function handler(request: Request): Promise<Response> {
     status: returnValue?.ok === false ? 500 : undefined,
     headers: {
       'Content-type': 'text/html',
-      vary: 'accept',
     },
   })
 }

packages/plugin-rsc/examples/starter/src/framework/entry.rsc.tsx

@@ -71,7 +71,6 @@ export default async function handler(request: Request): Promise<Response> {
       status: returnValue?.ok === false ? 500 : undefined,
       headers: {
         'content-type': 'text/x-component;charset=utf-8',
-        vary: 'accept',
       },
     })
   }
@@ -94,7 +93,6 @@ export default async function handler(request: Request): Promise<Response> {
     status: returnValue?.ok === false ? 500 : undefined,
     headers: {
       'Content-type': 'text/html',
-      vary: 'accept',
     },
   })
 }