Revert "doc: add social cards generation support in sphinxext-opengraph (python#129085)"

This reverts commit 382340d.

Author: AA-Turner

Doc/Makefile

@@ -13,8 +13,7 @@ JOBS         = auto
 PAPER        =
 SOURCES      =
 DISTVERSION  = $(shell $(PYTHON) tools/extensions/patchlevel.py)
-IS_PYTHON_BUILD = $(shell $(PYTHON) -c 'import sysconfig; print("true") if sysconfig.is_python_build() else None')
-REQUIREMENTS = $(if $(IS_PYTHON_BUILD),requirements.txt,requirements-no-build.txt)
+REQUIREMENTS = requirements.txt
 SPHINXERRORHANDLING = --fail-on-warning
 
 # Internal variables.