fix: uniformize arduino examples

.clang-format

@@ -1,3 +1,5 @@
+---
+Language: Cpp
 BasedOnStyle: Google
 IndentWidth: 4
 ColumnLimit: 120

examples/arduino/z_get.ino

@@ -120,6 +120,9 @@ void loop() {
     }
 }
 #else
-void setup() { Serial.println("ERROR: Zenoh pico was compiled without Z_FEATURE_QUERY but this example requires it."); }
+void setup() {
+    Serial.println("ERROR: Zenoh pico was compiled without Z_FEATURE_QUERY but this example requires it.");
+    return;
+}
 void loop() {}
 #endif

examples/arduino/z_pub.ino

@@ -111,6 +111,7 @@ void loop() {
 #else
 void setup() {
     Serial.println("ERROR: Zenoh pico was compiled without Z_FEATURE_PUBLICATION but this example requires it.");
+    return;
 }
 void loop() {}
 #endif

examples/arduino/z_pull.ino

@@ -112,6 +112,7 @@ void loop() {
 #else
 void setup() {
     Serial.println("ERROR: Zenoh pico was compiled without Z_FEATURE_SUBSCRIPTION but this example requires it.");
+    return;
 }
 void loop() {}
 #endif

examples/arduino/z_queryable.ino

@@ -111,6 +111,7 @@ void loop() { delay(5000); }
 #else
 void setup() {
     Serial.println("ERROR: Zenoh pico was compiled without Z_FEATURE_QUERYABLE but this example requires it.");
+    return;
 }
 void loop() {}
 #endif

examples/arduino/z_sub.ino

@@ -109,6 +109,7 @@ void loop() { delay(5000); }
 #else
 void setup() {
     Serial.println("ERROR: Zenoh pico was compiled without Z_FEATURE_SUBSCRIPTION but this example requires it.");
+    return;
 }
 void loop() {}
 #endif