[camera, camera_encoder] Remove stored RAMAllocator member (#13997)

esphome/components/camera/buffer_impl.cpp

@@ -3,18 +3,22 @@
 namespace esphome::camera {
 
 BufferImpl::BufferImpl(size_t size) {
-  this->data_ = this->allocator_.allocate(size);
+  RAMAllocator<uint8_t> allocator;
+  this->data_ = allocator.allocate(size);
   this->size_ = size;
 }
 
 BufferImpl::BufferImpl(CameraImageSpec *spec) {
-  this->data_ = this->allocator_.allocate(spec->bytes_per_image());
+  RAMAllocator<uint8_t> allocator;
+  this->data_ = allocator.allocate(spec->bytes_per_image());
   this->size_ = spec->bytes_per_image();
 }
 
 BufferImpl::~BufferImpl() {
-  if (this->data_ != nullptr)
-    this->allocator_.deallocate(this->data_, this->size_);
+  if (this->data_ != nullptr) {
+    RAMAllocator<uint8_t> allocator;
+    allocator.deallocate(this->data_, this->size_);
+  }
 }
 
 }  // namespace esphome::camera