Bump idna from 3.11 to 3.15 in /requirements/docs (#84)

Author: kurtmckee

requirements/docs/requirements.txt

@@ -4,7 +4,7 @@ certifi==2026.2.25 ; python_version >= "3.10"
 charset-normalizer==3.4.4 ; python_version >= "3.10"
 colorama==0.4.6 ; python_version >= "3.10" and sys_platform == "win32"
 docutils==0.21.2 ; python_version >= "3.10"
-idna==3.11 ; python_version >= "3.10"
+idna==3.15 ; python_version >= "3.10"
 imagesize==1.4.1 ; python_version >= "3.10"
 jinja2==3.1.6 ; python_version >= "3.10"
 markupsafe==3.0.3 ; python_version >= "3.10"