runJs: correct MIME type for wasm files (#1562)

runJs task: correct MIME type for wasm files

Currently wasm files are served with `application/octet-stream` which is not working.
I understand that wasm is not supported by Korge yet, but it can still be used i.e. to offload heavy game computations.

buildSrc/src/main/kotlin/korlibs/korge/gradle/util/HttpServerTools.kt

@@ -174,6 +174,7 @@ fun File.miniMimeType() = when (this.extension.toLowerCase()) {
     "jpg", "jpeg" -> "image/jpeg"
     "svg" -> "image/svg+xml"
     "mp3" -> "audio/mpeg"
+    "wasm" -> "application/wasm"
     else -> if (this.exists()) Files.probeContentType(this.toPath()) ?: "application/octet-stream" else "text/plain"
 }