Bump urllib3 from 2.1.0 to 2.6.0 in /llvm/docs

Bumps [urllib3](https://github.com/urllib3/urllib3) from 2.1.0 to 2.6.0.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@2.1.0...2.6.0)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-version: 2.6.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

llvm/docs/requirements-hashed.txt

@@ -365,7 +365,7 @@ sphinxcontrib-serializinghtml==1.1.9 \
     --hash=sha256:0c64ff898339e1fac29abd2bf5f11078f3ec413cfe9c046d3120d7ca65530b54 \
     --hash=sha256:9b36e503703ff04f20e9675771df105e58aa029cfcbc23b8ed716019b7416ae1
     # via sphinx
-urllib3==2.1.0 \
-    --hash=sha256:55901e917a5896a349ff771be919f8bd99aff50b79fe58fec595eb37bbc56bb3 \
-    --hash=sha256:df7aa8afb0148fa78488e7899b2c59b5f4ffcfa82e6c54ccb9dd37c1d7b52d54
+urllib3==2.6.0 \
+    --hash=sha256:c90f7a39f716c572c4e3e58509581ebd83f9b59cced005b7db7ad2d22b0db99f \
+    --hash=sha256:cb9bcef5a4b345d5da5d145dc3e30834f58e8018828cbc724d30b4cb7d4d49f1
     # via requests