fix(deps): Bump @google-cloud/pubsub from 3.7.3 to 4.0.0 (#22)

Bumps [@google-cloud/pubsub](https://github.com/googleapis/nodejs-pubsub) from 3.7.3 to 4.0.0.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://github.com/googleapis/nodejs-pubsub/releases"><code>@​google-cloud/pubsub</code>'s releases</a>.</em></p>
<blockquote>
<h2>v4.0.0</h2>
<h2><a href="https://github.com/googleapis/nodejs-pubsub/compare/v3.7.3...v4.0.0">4.0.0</a> (2023-08-03)</h2>
<h3>⚠ BREAKING CHANGES</h3>
<ul>
<li>node 12 eos (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1774">#1774</a>) (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1784">#1784</a>)</li>
</ul>
<h3>Features</h3>
<ul>
<li>Node 12 eos (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1774">#1774</a>) (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1784">#1784</a>) (<a href="https://github.com/googleapis/nodejs-pubsub/commit/47b83c18c543a7c8763256f79927a7340db56568">47b83c1</a>)</li>
</ul>
<h3>Bug Fixes</h3>
<ul>
<li>Fix typings for IAM methods (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1785">#1785</a>) (<a href="https://github.com/googleapis/nodejs-pubsub/commit/9a6bdbce952c81cb1a43fecbce16a3e3ab0f1420">9a6bdbc</a>)</li>
</ul>
</blockquote>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/googleapis/nodejs-pubsub/blob/main/CHANGELOG.md"><code>@​google-cloud/pubsub</code>'s changelog</a>.</em></p>
<blockquote>
<h2><a href="https://github.com/googleapis/nodejs-pubsub/compare/v3.7.3...v4.0.0">4.0.0</a> (2023-08-03)</h2>
<h3>⚠ BREAKING CHANGES</h3>
<ul>
<li>node 12 eos (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1774">#1774</a>) (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1784">#1784</a>)</li>
</ul>
<h3>Features</h3>
<ul>
<li>Node 12 eos (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1774">#1774</a>) (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1784">#1784</a>) (<a href="https://github.com/googleapis/nodejs-pubsub/commit/47b83c18c543a7c8763256f79927a7340db56568">47b83c1</a>)</li>
</ul>
<h3>Bug Fixes</h3>
<ul>
<li>Fix typings for IAM methods (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1785">#1785</a>) (<a href="https://github.com/googleapis/nodejs-pubsub/commit/9a6bdbce952c81cb1a43fecbce16a3e3ab0f1420">9a6bdbc</a>)</li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/6c38e7bd29d1351830c80ade7162b6d5cf9cbe1e"><code>6c38e7b</code></a> chore(main): release 4.0.0 (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1791">#1791</a>)</li>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/c54307eeff720ecbfd4f4f87ba77ebdadf1d147d"><code>c54307e</code></a> docs: fix node release schedule link (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1794">#1794</a>)</li>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/6533978887582d39b65fd4d08572118b3fed7ff0"><code>6533978</code></a> build: update Node.js version and base Debian version (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1793">#1793</a>)</li>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/9a6bdbce952c81cb1a43fecbce16a3e3ab0f1420"><code>9a6bdbc</code></a> fix: fix typings for IAM methods (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1785">#1785</a>)</li>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/0772e963254e39e31a9fba64c6d1e9b028ed6042"><code>0772e96</code></a> build: force-update gts version (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1792">#1792</a>)</li>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/933975e4d9f196cab4af09aac9a8bb240ae6f27d"><code>933975e</code></a> chore(deps): upgrade dependencies for Node.js images (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1789">#1789</a>)</li>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/d8577919aedf5dbf3bdf9897dfb5a52179b6066f"><code>d857791</code></a> chore(deps): update dependency <code>@​google-cloud/bigquery</code> to v7 (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1790">#1790</a>)</li>
<li><a href="https://github.com/googleapis/nodejs-pubsub/commit/47b83c18c543a7c8763256f79927a7340db56568"><code>47b83c1</code></a> feat!: node 12 eos (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1774">#1774</a>) (<a href="https://redirect.github.com/googleapis/nodejs-pubsub/issues/1784">#1784</a>)</li>
<li>See full diff in <a href="https://github.com/googleapis/nodejs-pubsub/compare/v3.7.3...v4.0.0">compare view</a></li>
</ul>
</details>
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