docs: Pin to the exact versions that worked last

Author: jmgate

doc/requirements.txt

@@ -1,8 +1,8 @@
 # Requirements for building the `shell-logger` documentation.
 
-sphinx>=8.0.0
-sphinx-argparse
-sphinx-autodoc-typehints
-sphinx-copybutton
-sphinx-rtd-theme>=2.0.0
-sphinxcontrib-programoutput
+sphinx==7.4.7
+sphinx-argparse==0.5.2
+sphinx-autodoc-typehints==2.3.0
+sphinx-copybutton==0.5.2
+sphinx-rtd-theme==2.0.0
+sphinxcontrib-programoutput==0.17