Bump indexmap from 1.8.0 to 1.8.1 (#1988)

Bumps [indexmap](https://github.com/bluss/indexmap) from 1.8.0 to 1.8.1.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/bluss/indexmap/blob/master/RELEASES.md">indexmap's changelog</a>.</em></p>
<blockquote>
<ul>
<li>
<p>1.8.1</p>
<ul>
<li>The new <code>IndexSet::replace_full</code> will return the index of the item along
with the replaced value, if any, by <a href="https://github.com/zakcutner"><code>@​zakcutner</code></a> in PR <a href="https://github-redirect.dependabot.com/bluss/indexmap/pull/222">222</a>.</li>
</ul>
</li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/bluss/indexmap/commit/275379c489b483e69d9a61265e9026f42a415219"><code>275379c</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bluss/indexmap/issues/222">#222</a> from zakcutner/replace-full</li>
<li><a href="https://github.com/bluss/indexmap/commit/12162abeb0924c0a48c4bb89c12a9bc84460973c"><code>12162ab</code></a> Release 1.8.1</li>
<li><a href="https://github.com/bluss/indexmap/commit/feb816c4b885406fecdac751a480ee1bd269085a"><code>feb816c</code></a> Add a <code>replace_full</code> method on <code>IndexSet</code></li>
<li><a href="https://github.com/bluss/indexmap/commit/d6a9dd6c919798ff25220660a6603b7c89b85b5d"><code>d6a9dd6</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bluss/indexmap/issues/218">#218</a> from erickt/miri</li>
<li><a href="https://github.com/bluss/indexmap/commit/4dd6619b4ce609f196c0b521b6382225c348a365"><code>4dd6619</code></a> Add miri builder</li>
<li><a href="https://github.com/bluss/indexmap/commit/10ee11e56c624964ffc1f4da76c8d6e84bdea43d"><code>10ee11e</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bluss/indexmap/issues/216">#216</a> from cuviper/dev-dependencies</li>
<li><a href="https://github.com/bluss/indexmap/commit/98de9abe37965efa73daf533fd92b799a5a25947"><code>98de9ab</code></a> Update dev-dependencies</li>
<li>See full diff in <a href="https://github.com/bluss/indexmap/compare/1.8.0...1.8.1">compare view</a></li>
</ul>
</details>
<br />


[![Dependabot compatibility score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=indexmap&package-manager=cargo&previous-version=1.8.0&new-version=1.8.1)](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores)

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
- `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)


</details>

boa_engine/Cargo.toml

@@ -33,7 +33,7 @@ rustc-hash = "1.1.0"
 num-bigint = { version = "0.4.3", features = ["serde"] }
 num-integer = "0.1.44"
 bitflags = "1.3.2"
-indexmap = "1.8.0"
+indexmap = "1.8.1"
 ryu-js = "0.2.2"
 chrono = "0.4.19"
 fast-float = "0.2.0"