[taskboard] trim ssh known-host warnings

lib/dispatch.ts

@@ -68,7 +68,11 @@ function extractTagValue(tags: string[], prefix: string) {
 }
 
 function truncateOutput(output: string, maxLength = 4000) {
-  const trimmed = output.trim();
+  const trimmed = output
+    .split("\n")
+    .filter((line) => !line.startsWith("Warning: Permanently added "))
+    .join("\n")
+    .trim();
   if (trimmed.length <= maxLength) {
     return trimmed;
   }