Add the identifier field to the license object

[irevoire]

Hey,

One of our users noticed that the identifier field was missing in the license object: meilisearch/open-api#15

From what I see in the openAPI specification, they're right:

[juhaku]

The identifier was added there not long ago and should be set automatically if I remember right:

utoipa/utoipa/src/openapi/info.rs

Line 260 in 6faef38

pub fn identifier<S: Into<String>>(mut self, identifier: Option<S>) -> Self {

Also it is set in the utoipa-gen by resolving it from CARGO_PKG_LICENSE field

utoipa/utoipa-gen/src/openapi/info.rs

Lines 44 to 51 in 6faef38

	let license = std::env::var("CARGO_PKG_LICENSE")
	.ok()
	.map(|spdx_expr| License {
	name: Cow::Owned(spdx_expr.clone()),
	// CARGO_PKG_LICENSE contains an SPDX expression as described in the Cargo Book.
	// It can be set to `info.license.identifier`.
	identifier: Cow::Owned(spdx_expr),
	..Default::default()

It should be possible to set it via #[openapi(info(identifier = ...))] attribute as well but then the whole info need be manually added as well.

[irevoire]

Ah ok, from what I understand it is already fixed but not released yet, is that correct?

It should be possible to set it via #[openapi(info(identifier = ...))] attribute as well but then the whole info need be manually added as well.

Not really interested in writing it myself, utoipa-gen is already able to read our license.