Remove making believe we are ReadTheDocs in CI builds.

New sphinxext.opengraph seems to resolve the issue.

Author: Julian

docs/requirements.txt

@@ -97,7 +97,7 @@ sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
 sphinxcontrib-spelling==7.7.0
     # via -r docs/requirements.in
-sphinxext-opengraph==0.7.2
+sphinxext-opengraph==0.7.3
     # via -r docs/requirements.in
 unidecode==1.3.6
     # via sphinx-autoapi

tox.ini

@@ -95,10 +95,6 @@ commands = {envpython} -m mypy --config {toxinidir}/pyproject.toml {posargs} {to
 
 [testenv:docs-dirhtml]
 commands = {envpython} -m sphinx -b dirhtml {toxinidir}/docs/ {envtmpdir}/build {posargs:-a -n -q -T -W}
-# REMOVEME: See https://github.com/wpilibsuite/sphinxext-opengraph/issues/87
-setenv =
-    {[testenv]setenv}
-    READTHEDOCS=true
 deps =
     -r{toxinidir}/docs/requirements.txt