Bump syn from 2.0.11 to 2.0.12 (#2770)

Bumps [syn](https://github.com/dtolnay/syn) from 2.0.11 to 2.0.12.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://github.com/dtolnay/syn/releases">syn's releases</a>.</em></p>
<blockquote>
<h2>2.0.12</h2>
<ul>
<li>Refer to <code>compile_error!</code> by absolute path in token stream produced by syn::Error::to_compile_error (<a href="https://redirect.github.com/dtolnay/syn/issues/1431">#1431</a>, thanks <a href="https://github.com/smoelius"><code>@​smoelius</code></a>)</li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/dtolnay/syn/commit/42e86861c568ba8e3dca9950b21abc61fe1ee1c0"><code>42e8686</code></a> Release 2.0.12</li>
<li><a href="https://github.com/dtolnay/syn/commit/cc7cf9914ec069b4e267991223446b02153ecb44"><code>cc7cf99</code></a> Absolute path to refer to core crate in compile_error expansion</li>
<li><a href="https://github.com/dtolnay/syn/commit/4d1fd262291eab8f2192fc889b1bae09e26f7bae"><code>4d1fd26</code></a> Merge pull request 1431 from smoelius/compile-error</li>
<li><a href="https://github.com/dtolnay/syn/commit/07601a83cc3a5acf94b544d658f27d1ce0e20562"><code>07601a8</code></a> Use <code>core</code> instead of <code>std</code></li>
<li><a href="https://github.com/dtolnay/syn/commit/710908453baa925203446db321c1423fd79d4eb2"><code>7109084</code></a> Qualify <code>compile_error!</code></li>
<li>See full diff in <a href="https://github.com/dtolnay/syn/compare/2.0.11...2.0.12">compare view</a></li>
</ul>
</details>
<br />


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</details>

boa_macros/Cargo.toml

@@ -13,6 +13,6 @@ proc-macro = true
 
 [dependencies]
 quote = "1.0.26"
-syn = { version = "2.0.11", features = ["full"] }
+syn = { version = "2.0.12", features = ["full"] }
 proc-macro2 = "1.0"
 synstructure = "0.13"