Add more precise dependencies constrains for readthedocs to solve the issue with dependency resolution and performance.

Author: dbalabka

doc/requirements-docs.txt

@@ -1,14 +1,14 @@
 # We have to set minimal versions to avoid searches over old versions whose metadata is incompatible with the latest pip
-numpydoc>=0.6.0
-docutils>=0.15.2
-sphinx
-dask-sphinx-theme>=3.0.5
+numpydoc<2,>=1.5.0
+docutils<0.17,>=0.16
+sphinx<5,>=4.0.0
+dask-sphinx-theme<4,>=3.0.5
 # FIXME: This workaround is required until we have sphinx>=5, as enabled by
 #        dask-sphinx-theme no longer pinning sphinx-book-theme==0.2.0. This is
 #        tracked in https://github.com/dask/dask-sphinx-theme/issues/68.
 #
-sphinxcontrib-applehelp<1.0.5
-sphinxcontrib-devhelp<1.0.6
-sphinxcontrib-htmlhelp<2.0.5
-sphinxcontrib-serializinghtml<1.1.10
-sphinxcontrib-qthelp<1.0.7
+sphinxcontrib-applehelp<1.0.5,>=1.0.0
+sphinxcontrib-devhelp<1.0.6,>=1.0.0
+sphinxcontrib-htmlhelp<2.0.5,>=2.0.0
+sphinxcontrib-serializinghtml<1.1.10,>=1.0.0
+sphinxcontrib-qthelp<1.0.7,>=1.0.0