message: fix(c-api) Remove useless `unsafe` marker.
diff: @@ -186,7 +186,7 @@ pub extern "C" fn wasmer_metering_new(
  ///
  /// See module's documentation.
  #[no_mangle]
  -pub unsafe extern "C" fn wasmer_metering_delete(_metering: Option<Box<wasmer_metering_t>>) {}
  +pub extern "C" fn wasmer_metering_delete(_metering: Option<Box<wasmer_metering_t>>) {}
  /// Returns the remaining metering points. Zero means points are
  /// exhausted, otherwise it returns the number of points.
  @@ -195,7 +195,7 @@ pub unsafe extern "C" fn wasmer_metering_delete(_metering: Option<Box<wasmer_met
  ///
  /// See module's documentation.
  #[no_mangle]
  -pub unsafe extern "C" fn wasmer_metering_get_remaining_points(instance: &wasm_instance_t) -> u64 {
  +pub extern "C" fn wasmer_metering_get_remaining_points(instance: &wasm_instance_t) -> u64 {
  match get_remaining_points(&instance.inner) {
  MeteringPoints::Remaining(value) => value,
  MeteringPoints::Exhausted => 0,
  @@ -275,10 +275,7 @@ pub unsafe extern "C" fn wasmer_metering_get_remaining_points(instance: &wasm_in
  /// # }
  /// ```
  #[no_mangle]
  -pub unsafe extern "C" fn wasmer_metering_set_remaining_points(
  - instance: &wasm_instance_t,
  - new_limit: u64,
  -) {
  +pub extern "C" fn wasmer_metering_set_remaining_points(instance: &wasm_instance_t, new_limit: u64) {
  set_remaining_points(&instance.inner, new_limit);
  }
  @@ -292,7 +289,7 @@ pub unsafe extern "C" fn wasmer_metering_set_remaining_points(
  ///
  /// See module's documentation.
  #[no_mangle]
  -pub unsafe extern "C" fn wasmer_metering_as_middleware(
  +pub extern "C" fn wasmer_metering_as_middleware(
  metering: Option<Box<wasmer_metering_t>>,
  ) -> Option<Box<wasmer_middleware_t>> {
  let metering = metering?;
  