Update Rust crate mdbook to v0.4.42 (#20629)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [mdbook](https://redirect.github.com/rust-lang/mdBook) | dependencies
| patch | `0.4.40` -> `0.4.42` |

---

### Release Notes

<details>
<summary>rust-lang/mdBook (mdbook)</summary>

###
[`v0.4.42`](https://redirect.github.com/rust-lang/mdBook/blob/HEAD/CHANGELOG.md#mdBook-0442)

[Compare
Source](https://redirect.github.com/rust-lang/mdBook/compare/v0.4.41...v0.4.42)


[v0.4.41...v0.4.42](https://redirect.github.com/rust-lang/mdBook/compare/v0.4.41...v0.4.42)

##### Fixed

-   Fixed chapter list folding.
[#&#8203;2473](https://redirect.github.com/rust-lang/mdBook/pull/2473)

###
[`v0.4.41`](https://redirect.github.com/rust-lang/mdBook/blob/HEAD/CHANGELOG.md#mdBook-0441)

[Compare
Source](https://redirect.github.com/rust-lang/mdBook/compare/v0.4.40...v0.4.41)


[v0.4.40...v0.4.41](https://redirect.github.com/rust-lang/mdBook/compare/v0.4.40...v0.4.41)

**Note:** If you have a custom `index.hbs` theme file, you will need to
update it to the latest version.

##### Added

-   Added preliminary support for Rust 2024 edition.
[#&#8203;2398](https://redirect.github.com/rust-lang/mdBook/pull/2398)
-   Added a full example of the remove-emphasis preprocessor.
[#&#8203;2464](https://redirect.github.com/rust-lang/mdBook/pull/2464)

##### Changed

-   Adjusted styling of clipboard/play icons.
[#&#8203;2421](https://redirect.github.com/rust-lang/mdBook/pull/2421)
-   Updated to handlebars v6.
[#&#8203;2416](https://redirect.github.com/rust-lang/mdBook/pull/2416)
-   Attr and section rules now have specific code highlighting.
[#&#8203;2448](https://redirect.github.com/rust-lang/mdBook/pull/2448)
- The sidebar is now loaded from a common file, significantly reducing
the book size when there are many chapters.
[#&#8203;2414](https://redirect.github.com/rust-lang/mdBook/pull/2414)
-   Updated dependencies.
[#&#8203;2470](https://redirect.github.com/rust-lang/mdBook/pull/2470)

##### Fixed

-   Improved theme support when JavaScript is disabled.
[#&#8203;2454](https://redirect.github.com/rust-lang/mdBook/pull/2454)
-   Fixed broken themes when localStorage has an invalid theme id.
[#&#8203;2463](https://redirect.github.com/rust-lang/mdBook/pull/2463)
- Adjusted the line-height of superscripts (and footnotes) to avoid
adding extra space between lines.
[#&#8203;2465](https://redirect.github.com/rust-lang/mdBook/pull/2465)

</details>

---

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---

Release Notes:

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Cargo.lock

@@ -5274,11 +5274,12 @@ dependencies = [
 
 [[package]]
 name = "handlebars"
-version = "5.1.2"
+version = "6.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d08485b96a0e6393e9e4d1b8d48cf74ad6c063cd905eb33f42c1ce3f0377539b"
+checksum = "fd4ccde012831f9a071a637b0d4e31df31c0f6c525784b35ae76a9ac6bc1e315"
 dependencies = [
  "log",
+ "num-order",
  "pest",
  "pest_derive",
  "serde",
@@ -5652,7 +5653,7 @@ dependencies = [
  "httpdate",
  "itoa",
  "pin-project-lite",
- "socket2 0.5.7",
+ "socket2 0.4.10",
  "tokio",
  "tower-service",
  "tracing",
@@ -6937,9 +6938,9 @@ dependencies = [
 
 [[package]]
 name = "mdbook"
-version = "0.4.40"
+version = "0.4.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b45a38e19bd200220ef07c892b0157ad3d2365e5b5a267ca01ad12182491eea5"
+checksum = "7624879735513024d323e7267a0b3a7176aceb0db537939beb4ee31d9e8945e3"
 dependencies = [
  "ammonia",
  "anyhow",
@@ -6949,7 +6950,7 @@ dependencies = [
  "elasticlunr-rs",
  "env_logger 0.11.5",
  "futures-util",
- "handlebars 5.1.2",
+ "handlebars 6.2.0",
  "ignore",
  "log",
  "memchr",
@@ -7503,6 +7504,21 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-modular"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17bb261bf36fa7d83f4c294f834e91256769097b3cb505d44831e0a179ac647f"
+
+[[package]]
+name = "num-order"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "537b596b97c40fcf8056d153049eb22f481c17ebce72a513ec9286e4986d1bb6"
+dependencies = [
+ "num-modular",
+]
+
 [[package]]
 name = "num-rational"
 version = "0.4.2"