tools(deps-dev): Update vimeo/psalm requirement from 6.8.9 to 6.9.4 in /tools/psalm (#520)

Updates the requirements on
[vimeo/psalm](https://github.com/vimeo/psalm) to permit the latest
version.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a
href="https://github.com/vimeo/psalm/releases">vimeo/psalm's
releases</a>.</em></p>
<blockquote>
<h2>6.9.4</h2>
<!-- raw HTML omitted -->
<h2>What's Changed</h2>
<h3>Fixes</h3>
<ul>
<li>Backport <a
href="https://redirect.github.com/vimeo/psalm/issues/11364">#11364</a>
to 6.x by <a
href="https://github.com/haas-dtv"><code>@​haas-dtv</code></a> in <a
href="https://redirect.github.com/vimeo/psalm/pull/11369">vimeo/psalm#11369</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a
href="https://github.com/vimeo/psalm/compare/6.9.3...6.9.4">https://github.com/vimeo/psalm/compare/6.9.3...6.9.4</a></p>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/vimeo/psalm/commit/e052de4275fb6cdbfedfef1d883a7e90732ea609"><code>e052de4</code></a>
Merge pull request <a
href="https://redirect.github.com/vimeo/psalm/issues/11369">#11369</a>
from haas-dtv/fix/11337-6.x</li>
<li><a
href="https://github.com/vimeo/psalm/commit/34de29b50fa654337a3e9ef3b7cf4609920318d8"><code>34de29b</code></a>
Add unit tests for string concatenation with other types</li>
<li><a
href="https://github.com/vimeo/psalm/commit/02342c980f4802a1df350b3d50e5845814a40a3b"><code>02342c9</code></a>
Update psalm-baseline.xml</li>
<li><a
href="https://github.com/vimeo/psalm/commit/0af16096958ee91d92acda25db5dbf312738ee9f"><code>0af1609</code></a>
Allow concatenation between (string|int) and similar types</li>
<li><a
href="https://github.com/vimeo/psalm/commit/189990791826d8aa2b72c106ea3b07656534dd61"><code>1899907</code></a>
Merge pull request <a
href="https://redirect.github.com/vimeo/psalm/issues/11367">#11367</a>
from danog/bump_php_version</li>
<li><a
href="https://github.com/vimeo/psalm/commit/b135e5687cf0331461f2c231db23fea8c396445d"><code>b135e56</code></a>
Bump PHP version</li>
<li><a
href="https://github.com/vimeo/psalm/commit/974a78b14ad555a0a276890b329d46dd7312323d"><code>974a78b</code></a>
Merge pull request <a
href="https://redirect.github.com/vimeo/psalm/issues/11366">#11366</a>
from vimeo/fix_11363</li>
<li><a
href="https://github.com/vimeo/psalm/commit/51fd960ecafc07b863e8f0fe5d966a38ea67938e"><code>51fd960</code></a>
Hotfix <a
href="https://redirect.github.com/vimeo/psalm/issues/11363">#11363</a></li>
<li><a
href="https://github.com/vimeo/psalm/commit/1cd777f270e9da12a61ce89ad3a472d0f72b0a7d"><code>1cd777f</code></a>
Fix multiplatform build for latest tag</li>
<li><a
href="https://github.com/vimeo/psalm/commit/81c8a77c0793d450fee40265cfe68891df11d505"><code>81c8a77</code></a>
Fix</li>
<li>Additional commits viewable in <a
href="https://github.com/vimeo/psalm/compare/6.8.9...6.9.4">compare
view</a></li>
</ul>
</details>
<br />


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 show <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@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>

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

tools/psalm/composer.json

@@ -7,7 +7,7 @@
     },
     "require-dev": {
         "roave/security-advisories": "dev-latest",
-        "vimeo/psalm": "6.8.9"
+        "vimeo/psalm": "6.9.4"
     },
     "prefer-stable": true,
     "config": {