docs: remove pinned packages

- they keep generating security alerts
- also update our direct deps (sphinx, furo)

docs/requirements.in

@@ -1,3 +0,0 @@
-sphinx==7.2.6
-furo==2024.1.29
-sphinx-autobuild==2024.2.4

docs/requirements.txt

@@ -1,72 +1,3 @@
-#
-# This file is autogenerated by pip-compile with Python 3.10
-# by the following command:
-#
-#    pip-compile requirements.in
-#
-alabaster==0.7.16
-    # via sphinx
-babel==2.14.0
-    # via sphinx
-beautifulsoup4==4.12.3
-    # via furo
-certifi==2024.2.2
-    # via requests
-charset-normalizer==3.3.2
-    # via requests
-colorama==0.4.6
-    # via sphinx-autobuild
-docutils==0.20.1
-    # via sphinx
-furo==2024.1.29
-    # via -r requirements.in
-idna==3.7
-    # via requests
-imagesize==1.4.1
-    # via sphinx
-jinja2==3.1.4
-    # via sphinx
-livereload==2.6.3
-    # via sphinx-autobuild
-markupsafe==2.1.5
-    # via jinja2
-packaging==23.2
-    # via sphinx
-pygments==2.17.2
-    # via
-    #   furo
-    #   sphinx
-requests==2.31.0
-    # via sphinx
-six==1.16.0
-    # via livereload
-snowballstemmer==2.2.0
-    # via sphinx
-soupsieve==2.5
-    # via beautifulsoup4
-sphinx==7.2.6
-    # via
-    #   -r requirements.in
-    #   furo
-    #   sphinx-autobuild
-    #   sphinx-basic-ng
-sphinx-autobuild==2024.2.4
-    # via -r requirements.in
-sphinx-basic-ng==1.0.0b2
-    # via furo
-sphinxcontrib-applehelp==1.0.8
-    # via sphinx
-sphinxcontrib-devhelp==1.0.6
-    # via sphinx
-sphinxcontrib-htmlhelp==2.0.5
-    # via sphinx
-sphinxcontrib-jsmath==1.0.1
-    # via sphinx
-sphinxcontrib-qthelp==1.0.7
-    # via sphinx
-sphinxcontrib-serializinghtml==1.1.10
-    # via sphinx
-tornado==6.4
-    # via livereload
-urllib3==2.2.0
-    # via requests
+sphinx==7.3.7
+furo==2024.5.6
+sphinx-autobuild==2024.4.16