Fixed minimum version for sphinxcontrib-htmlhelp

Details:

* An earlier commit increased the minimum version of sphinxcontrib-htmlhelp from
  1.0.0 to 2.0.0 for all Python versions. However, 2.0.0 requires Python >= 3.6.
  Fixed that by using 1.0.0 as a minimum version for Python <=3.9 and 2.0.0
  as a minimum version for Python >=3.10. That is consistent with Sphinx 4.2.0
  which requires sphinxcontrib-htmlhelp>=2.0.0 also being used only for
  Python >=3.10.

Signed-off-by: Andreas Maier <andreas.r.maier@gmx.de>

Author: andy-maier

minimum-constraints.txt

@@ -270,7 +270,8 @@ smmap2==2.0.1; python_version == '2.7'
 snowballstemmer==1.2.1
 sphinxcontrib-applehelp==1.0.0; python_version >= '3.4'
 sphinxcontrib-devhelp==1.0.0; python_version >= '3.4'
-sphinxcontrib-htmlhelp==2.0.0; python_version >= '3.4'
+sphinxcontrib-htmlhelp==1.0.0; python_version >= '3.4' and python_version <= '3.9'
+sphinxcontrib-htmlhelp==2.0.0; python_version >= '3.10'
 sphinxcontrib-jsmath==1.0.0; python_version >= '3.4'
 sphinxcontrib-qthelp==1.0.0; python_version >= '3.4'
 sphinxcontrib-serializinghtml==1.1.5; python_version >= '3.4'