Update docs requirements, particularly to avoid an lxml CVE.

CVE-2022-2309

See https://github.com/python-jsonschema/jsonschema/security/dependabot/2.

docs/requirements.txt

@@ -14,21 +14,21 @@ beautifulsoup4==4.11.1
     # via furo
 certifi==2022.6.15
     # via requests
-charset-normalizer==2.0.12
+charset-normalizer==2.1.0
     # via requests
 docutils==0.18.1
     # via sphinx
-furo==2022.6.4.1
+furo==2022.6.21
     # via -r docs/requirements.in
 idna==3.3
     # via requests
-imagesize==1.3.0
+imagesize==1.4.1
     # via sphinx
 jinja2==3.1.2
     # via sphinx
 file:.#egg=jsonschema
     # via -r docs/requirements.in
-lxml==4.9.0
+lxml==4.9.1
     # via -r docs/requirements.in
 markupsafe==2.1.1
     # via jinja2
@@ -46,7 +46,7 @@ pyrsistent==0.18.1
     # via jsonschema
 pytz==2022.1
     # via babel
-requests==2.28.0
+requests==2.28.1
     # via sphinx
 snowballstemmer==2.2.0
     # via sphinx
@@ -61,7 +61,7 @@ sphinx==5.0.2
     #   sphinxcontrib-spelling
 sphinx-autodoc-typehints==1.18.3
     # via -r docs/requirements.in
-sphinx-basic-ng==0.0.1a11
+sphinx-basic-ng==0.0.1a12
     # via furo
 sphinxcontrib-applehelp==1.0.2
     # via sphinx
@@ -75,7 +75,7 @@ sphinxcontrib-qthelp==1.0.3
     # via sphinx
 sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
-sphinxcontrib-spelling==7.5.0
+sphinxcontrib-spelling==7.6.0
     # via -r docs/requirements.in
 urllib3==1.26.9
     # via requests