serde_with v3.15.0

Added

• Added error inspection to VecSkipError and MapSkipError by @michelhe (#878)
  This allows interacting with the previously hidden error, for example for logging.
  Checkout the newly added example to both types.

• Allow documenting the types generated by serde_conv!.
  The serde_conv! macro now acceps outer attributes before the optional visibility modifier.
  This allow adding doc comments in the shape of #[doc = "..."] or any other attributes, such as lint modifiers.

  serde_conv!(
      #[doc = "Serialize bools as string"]
      #[allow(dead_code)]
      pub BoolAsString,
      bool,
      |x: &bool| ::std::string::ToString::to_string(x),
      |x: ::std::string::String| x.parse()
  );

• Add support for hashbrown v0.16 (#877)

  This extends the existing support for hashbrown v0.14 and v0.15 to the newly released version.

Changed

• Bump MSRV to 1.76, since that is required for toml dev-dependency.