Fix failure to run executable targets on Windows

src/utils.ts

@@ -168,7 +168,10 @@ export async function genEnvFile(buildDir: string) {
   // Load into a dict because vscode.ProcessExecution() does not support envFile.
   _envDict = {};
   const data = await fs.promises.readFile(envfile);
-  for (const i of data.toString().split(/\r?\n/)) {
+  for (const i of data
+    .toString()
+    .split(/\r?\n/)
+    .filter((i) => i)) {
     // Poor man's i.split("=", 1), JS won't return part after first equal sign.
     // Value is quoted, remove first and last " char and also possible \r ending.
     const index = i.indexOf("=");