chore(deps): bump idna from 3.10 to 3.15 in /docs

Bumps [idna](https://github.com/kjd/idna) from 3.10 to 3.15.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.md)
- [Commits](kjd/idna@v3.10...v3.15)

---
updated-dependencies:
- dependency-name: idna
  dependency-version: '3.15'
  dependency-type: indirect
...

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

Author: dependabot[bot]

docs/requirements.txt

@@ -147,9 +147,9 @@ griffe==1.13.0 \
     --hash=sha256:246ea436a5e78f7fbf5f24ca8a727bb4d2a4b442a2959052eea3d0bfe9a076e0 \
     --hash=sha256:470fde5b735625ac0a36296cd194617f039e9e83e301fcbd493e2b58382d0559
     # via mkdocstrings-python
-idna==3.10 \
-    --hash=sha256:12f65c9b470abda6dc35cf8e63cc574b1c52b11df2c86030af0ac09b01b13ea9 \
-    --hash=sha256:946d195a0d259cbba61165e88e65941f16e9b36ea6ddb97f00452bae8b1287d3
+idna==3.15 \
+    --hash=sha256:048adeaf8c2d788c40fee287673ccaa74c24ffd8dcf09ffa555a2fbb59f10ac8 \
+    --hash=sha256:ca962446ea538f7092a95e057da437618e886f4d349216d2b1e294abfdb65fdc
     # via requests
 jinja2==3.1.6 \
     --hash=sha256:0137fb05990d35f1275a587e9aee6d56da821fc83491a0fb838183be43f66d6d \