Update git2 requirement from 0.13.25 to 0.14.0 in /boa_tester (#1868)

Updates the requirements on [git2](https://github.com/rust-lang/git2-rs) to permit the latest version.
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<summary>Commits</summary>
<ul>
<li><a href="30f013875e"><code>30f0138</code></a> Bump versions</li>
<li><a href="7603309738"><code>7603309</code></a> Update libgit2 (<a href="https://github-redirect.dependabot.com/rust-lang/git2-rs/issues/527">#527</a>)</li>
<li><a href="d70b64599a"><code>d70b645</code></a> Make all callbacks optional in libgit2-sys</li>
<li><a href="d34e49cc12"><code>d34e49c</code></a> Remove unnecessary parentheses. (<a href="https://github-redirect.dependabot.com/rust-lang/git2-rs/issues/526">#526</a>)</li>
<li><a href="08114526f8"><code>0811452</code></a> Add Repository::fetchhead_to_annotated_commit (<a href="https://github-redirect.dependabot.com/rust-lang/git2-rs/issues/524">#524</a>)</li>
<li><a href="666aeab349"><code>666aeab</code></a> Bump version numbers of crates</li>
<li><a href="ecd56b00fb"><code>ecd56b0</code></a> Tie Patch lifetime to its input buffers (<a href="https://github-redirect.dependabot.com/rust-lang/git2-rs/issues/523">#523</a>)</li>
<li><a href="9071a87bad"><code>9071a87</code></a> Add <code>Branch::get_mut()</code> (<a href="https://github-redirect.dependabot.com/rust-lang/git2-rs/issues/522">#522</a>)</li>
<li><a href="850c9b96d5"><code>850c9b9</code></a> Update the libgit2 submodule to v0.99.0 (<a href="https://github-redirect.dependabot.com/rust-lang/git2-rs/issues/520">#520</a>)</li>
<li><a href="147c5b4f02"><code>147c5b4</code></a> Add examples (<a href="https://github-redirect.dependabot.com/rust-lang/git2-rs/issues/519">#519</a>)</li>
<li>Additional commits viewable in <a href="https://github.com/rust-lang/git2-rs/compare/0.13.25...git2-curl-0.14.0">compare view</a></li>
</ul>
</details>
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</details>

boa_tester/Cargo.toml

@@ -40,7 +40,7 @@ regex = "1.5.4"
 once_cell = "1.9.0"
 colored = "2.0.0"
 fxhash = "0.2.1"
-git2 = "0.13.25"
+git2 = "0.14.0"
 hex = "0.4.3"
 num-format = "0.4.0"
 gc = { version = "0.4.1", features = ["derive"] }