[pulse_counter] Fix build failure when use_pcnt is false (#14111)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

esphome/components/pulse_counter/pulse_counter_sensor.h

@@ -8,10 +8,10 @@
 
 #if defined(USE_ESP32)
 #include <soc/soc_caps.h>
-#ifdef SOC_PCNT_SUPPORTED
+#if defined(SOC_PCNT_SUPPORTED) && __has_include(<driver/pulse_cnt.h>)
 #include <driver/pulse_cnt.h>
 #define HAS_PCNT
-#endif  // SOC_PCNT_SUPPORTED
+#endif  // defined(SOC_PCNT_SUPPORTED) && __has_include(<driver/pulse_cnt.h>)
 #endif  // USE_ESP32
 
 namespace esphome {

tests/components/pulse_counter/test-no-pcnt.esp32-idf.yaml

@@ -0,0 +1,10 @@
+sensor:
+  - platform: pulse_counter
+    name: Pulse Counter
+    pin: 4
+    use_pcnt: false
+    count_mode:
+      rising_edge: INCREMENT
+      falling_edge: DECREMENT
+    internal_filter: 13us
+    update_interval: 15s