fix: restore accidentally emptied fixture file

Prettier accidentally cleared fixture 15.json when formatting.
Restoring the original content.

Author: OttoAllmendinger

packages/wasm-utxo/test/fixtures/15.json

@@ -0,0 +1,20 @@
+{
+  "descriptor": "sh(pkh(03a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd))#dr3u9ynx",
+  "wasmNode": {
+    "Sh": {
+      "Ms": {
+        "Check": {
+          "PkH": {
+            "Single": "03a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd"
+          }
+        }
+      }
+    }
+  },
+  "ast": {
+    "sh": {
+      "pkh": "03a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd"
+    }
+  }
+}
+