serde_with v3.13.0

Added

• Added support for schemars v0.9.0 under the schemars_0_9 feature flag by @swlynch99 (#849)
• Introduce SerializeDisplayAlt derive macro (#833)
  An alternative to the SerializeDisplay macro except instead of using the
  plain formatting like format!("{}", ...), it serializes with the
  Formatter::alternate flag set to true, like format!("{:#}", ...)

Changed

• Generalize serde_with::rust::unwrap_or_skip to support deserializing references by @beroal (#832)
• Bump MSRV to 1.71, since that is required for the jsonschema dev-dependency.
• Make serde_conv available without the std feature by @arilou (#839)
• Bump MSRV to 1.74, since that is required for schemars v0.9.0 by @swlynch99 (#849)

Fixed

• Make the DurationSeconds types and other variants more accessible even without std (#845)