fix: backward compat for server.preTransformRequests

Author: hi-ogawa

packages/vite/src/node/config.ts

@@ -1110,6 +1110,16 @@ export async function resolveConfig(
     configEnvironmentsSsr.dev.warmup = warmupOptions.ssrFiles
   }
 
+  // Backward compatibility: server.preTransformRequests -> environment.dev.preTransformRequests
+  if (typeof config.server?.preTransformRequests !== 'undefined') {
+    configEnvironmentsClient.dev.preTransformRequests =
+      config.server?.preTransformRequests
+    configEnvironmentsSsr ??= {}
+    configEnvironmentsSsr.dev ??= {}
+    configEnvironmentsSsr.dev.preTransformRequests ??=
+      config.server?.preTransformRequests
+  }
+
   // Backward compatibility: merge ssr into environments.ssr.config as defaults
   if (configEnvironmentsSsr) {
     configEnvironmentsSsr.optimizeDeps = mergeConfig(