Bump idna from 3.6 to 3.7 in /doc

Bumps [idna](https://github.com/kjd/idna) from 3.6 to 3.7.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v3.6...v3.7)

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

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

doc/requirements.txt

@@ -16,7 +16,7 @@ docutils==0.20.1
     # via
     #   sphinx
     #   sphinx-rtd-theme
-idna==3.6
+idna==3.7
     # via requests
 imagesize==1.4.1
     # via sphinx
@@ -29,18 +29,18 @@ packaging==23.2
 pygments==2.17.2
     # via sphinx
 readthedocs-sphinx-search==0.3.2
-    # via -r doc/requirements.in
+    # via -r requirements.in
 requests==2.31.0
     # via sphinx
 snowballstemmer==2.2.0
     # via sphinx
 sphinx==7.2.0
     # via
-    #   -r doc/requirements.in
+    #   -r requirements.in
     #   sphinx-rtd-theme
     #   sphinxcontrib-jquery
 sphinx-rtd-theme==2.0.0
-    # via -r doc/requirements.in
+    # via -r requirements.in
 sphinxcontrib-applehelp==1.0.8
     # via sphinx
 sphinxcontrib-devhelp==1.0.6