Bump urllib3 from 1.26.17 to 1.26.18 in /docs

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.17 to 1.26.18.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.17...1.26.18)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

docs/requirements.txt

@@ -100,7 +100,7 @@ mkdocs==1.5.3 \
 mkdocs-material==9.4.5 \
     --hash=sha256:0922e3e34d95dbf3f0c84fc817a233e1cbd5874830c6fd821d525ba90e0ce077 \
     --hash=sha256:efaa52843a8c64b99bcf5a97cf4ba57d410424828e3087b13c9b3954e8adb5ff
-    # via -r docs/requirements.in
+    # via -r requirements.in
 mkdocs-material-extensions==1.2 \
     --hash=sha256:27e2d1ed2d031426a6e10d5ea06989d67e90bb02acd588bc5673106b5ee5eedf \
     --hash=sha256:c767bd6d6305f6420a50f0b541b0c9966d52068839af97029be14443849fb8a1
@@ -279,9 +279,9 @@ six==1.16.0 \
     --hash=sha256:1e61c37477a1626458e36f7b1d82aa5c9b094fa4802892072e49de9c60c4c926 \
     --hash=sha256:8abb2f1d86890a2dfb989f9a77cfcfd3e47c2a354b01111771326f8aa26e0254
     # via python-dateutil
-urllib3==1.26.17 \
-    --hash=sha256:24d6a242c28d29af46c3fae832c36db3bbebcc533dd1bb549172cd739c82df21 \
-    --hash=sha256:94a757d178c9be92ef5539b8840d48dc9cf1b2709c9d6b588232a055c524458b
+urllib3==1.26.18 \
+    --hash=sha256:34b97092d7e0a3a8cf7cd10e386f401b3737364026c45e622aa02903dffe0f07 \
+    --hash=sha256:f8ecc1bba5667413457c529ab955bf8c67b45db799d159066261719e328580a0
     # via requests
 watchdog==2.2.0 \
     --hash=sha256:1893d425ef4fb4f129ee8ef72226836619c2950dd0559bba022b0818c63a7b60 \