Update Rust crate schemars to v1.2.0 (#17596)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [schemars](https://graham.cool/schemars/)
([source](https://redirect.github.com/GREsau/schemars)) |
workspace.dependencies | minor | `1.0.5` → `1.2.0` |

---

### Release Notes

<details>
<summary>GREsau/schemars (schemars)</summary>

###
[`v1.2.0`](https://redirect.github.com/GREsau/schemars/blob/HEAD/CHANGELOG.md#120---2025-12-25-)

[Compare
Source](https://redirect.github.com/GREsau/schemars/compare/v1.1.0...v1.2.0)

##### Added

- Add smol\_str03 feature
([#&#8203;486](https://redirect.github.com/GREsau/schemars/pull/486))

##### Changed

- Schemas generated for `HashMap`/`BTreeMap` with enum keys are now more
specific
([#&#8203;452](https://redirect.github.com/GREsau/schemars/pull/452))

###
[`v1.1.0`](https://redirect.github.com/GREsau/schemars/blob/HEAD/CHANGELOG.md#110---2025-11-05)

[Compare
Source](https://redirect.github.com/GREsau/schemars/compare/v1.0.5...v1.1.0)

##### Added

- Public functions that have no side-effects are now marked with
[`#[must_use]`](https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute)
so that they report a lint warning when the returned value is unused, as
this likely indicates a mistake.

##### Fixed

- Improve accuracy of schemas for flattened enums, in particular: unit
variants of externally-tagged enums, and enums wrapped in `Option<>`.
([#&#8203;464](https://redirect.github.com/GREsau/schemars/issues/464) /
[#&#8203;483](https://redirect.github.com/GREsau/schemars/pull/483))

</details>

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Cargo.lock

@@ -4245,9 +4245,9 @@ dependencies = [
 
 [[package]]
 name = "schemars"
-version = "1.0.5"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1317c3bf3e7df961da95b0a56a172a02abead31276215a0497241a7624b487ce"
+checksum = "54e910108742c57a770f492731f99be216a52fadd361b06c8fb59d74ccc267d2"
 dependencies = [
  "dyn-clone",
  "ref-cast",
@@ -4259,9 +4259,9 @@ dependencies = [
 
 [[package]]
 name = "schemars_derive"
-version = "1.0.5"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f760a6150d45dd66ec044983c124595ae76912e77ed0b44124cb3e415cce5d9"
+checksum = "4908ad288c5035a8eb12cfdf0d49270def0a268ee162b75eeee0f85d155a7c45"
 dependencies = [
  "proc-macro2",
  "quote",