build(deps): bump urllib3 from 1.26.17 to 1.26.18 in /owl-bot-postprocessor/synthtool/gcp/templates/java_library/.kokoro (#9975)

Bumps [urllib3](https://togithub.com/urllib3/urllib3) from 1.26.17 to 1.26.18.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://togithub.com/urllib3/urllib3/releases">urllib3's releases</a>.</em></p>
<blockquote>
<h2>1.26.18</h2>
<ul>
<li>Made body stripped from HTTP requests changing the request method to GET after HTTP 303 &quot;See Other&quot; redirect responses. (GHSA-g4mx-q9vg-27p4)</li>
</ul>
</blockquote>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://togithub.com/urllib3/urllib3/blob/main/CHANGES.rst">urllib3's changelog</a>.</em></p>
<blockquote>
<h1>1.26.18 (2023-10-17)</h1>
<ul>
<li>Made body stripped from HTTP requests changing the request method to GET after HTTP 303 &quot;See Other&quot; redirect responses.</li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://togithub.com/urllib3/urllib3/commit/9c2c2307dd1d6af504e09aac0326d86ee3597a0b"><code>9c2c230</code></a> Release 1.26.18 (<a href="https://redirect.github.com/urllib3/urllib3/issues/3159">#3159</a>)</li>
<li><a href="https://togithub.com/urllib3/urllib3/commit/b594c5ceaca38e1ac215f916538fb128e3526a36"><code>b594c5c</code></a> Merge pull request from GHSA-g4mx-q9vg-27p4</li>
<li><a href="https://togithub.com/urllib3/urllib3/commit/944f0eb134485f41bc531be52de12ba5a37bca73"><code>944f0eb</code></a> [1.26] Use vendored six in urllib3.contrib.securetransport</li>
<li>See full diff in <a href="https://togithub.com/urllib3/urllib3/compare/1.26.17...1.26.18">compare view</a></li>
</ul>
</details>
<br />


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Author: dependabot[bot]

owl-bot-postprocessor/synthtool/gcp/templates/java_library/.kokoro/requirements.in

@@ -25,7 +25,7 @@ google-cloud-storage==2.0.0
 google-resumable-media==2.3.3
 google-cloud-core==2.3.1
 typing-extensions==4.1.1
-urllib3==1.26.17
+urllib3==1.26.18
 zipp==3.6.0
 rsa==4.9
 six==1.16.0

owl-bot-postprocessor/synthtool/gcp/templates/java_library/.kokoro/requirements.txt

@@ -439,9 +439,9 @@ typing-extensions==4.1.1 \
     --hash=sha256:1a9462dcc3347a79b1f1c0271fbe79e844580bb598bafa1ed208b94da3cdcd42 \
     --hash=sha256:21c85e0fe4b9a155d0799430b0ad741cdce7e359660ccbd8b530613e8df88ce2
     # via -r requirements.in
-urllib3==1.26.17 \
-    --hash=sha256:24d6a242c28d29af46c3fae832c36db3bbebcc533dd1bb549172cd739c82df21 \
-    --hash=sha256:94a757d178c9be92ef5539b8840d48dc9cf1b2709c9d6b588232a055c524458b
+urllib3==1.26.18 \
+    --hash=sha256:34b97092d7e0a3a8cf7cd10e386f401b3737364026c45e622aa02903dffe0f07 \
+    --hash=sha256:f8ecc1bba5667413457c529ab955bf8c67b45db799d159066261719e328580a0
     # via
     #   -r requirements.in
     #   requests