refactor: cache vite runtime when using SSR

Close #31

src/server_renderer.ts

@@ -11,6 +11,7 @@ import { Vite } from '@adonisjs/vite'
 
 import { pathToFileURL } from 'node:url'
 import type { PageObject, RenderInertiaSsrApp, ResolvedConfig } from './types.js'
+import type { ViteRuntime } from 'vite/runtime'
 
 /**
  * Responsible for rendering page on the server
@@ -20,6 +21,8 @@ import type { PageObject, RenderInertiaSsrApp, ResolvedConfig } from './types.js
  *  bundle generated by Vite
  */
 export class ServerRenderer {
+  static runtime: ViteRuntime
+
   constructor(
     protected config: ResolvedConfig,
     protected vite?: Vite
@@ -40,8 +43,8 @@ export class ServerRenderer {
      * if we are in development mode
      */
     if (devServer) {
-      const runtime = await this.vite!.createRuntime()
-      render = await runtime.executeEntrypoint(this.config.ssr.entrypoint!)
+      ServerRenderer.runtime ??= await this.vite!.createRuntime()
+      render = await ServerRenderer.runtime.executeEntrypoint(this.config.ssr.entrypoint!)
     } else {
       /**
        * Otherwise, just import the SSR bundle