Fix partially failed during doc generation in Linux CI (#5097)

.azure-pipelines/Linux-CI.yml

@@ -130,7 +130,7 @@ jobs:
       if [ '$(documentation)' == '1' ]; then
         source venv/bin/activate
         pip install -r docs/docsgen/source/requirements.txt
-        cd docs/docsgen && make text -j auto
+        cd docs/docsgen && make text
       fi
     displayName: Test documentation
     continueOnError: true  # the documentation generates errors due to operators documentation

docs/docsgen/Makefile

@@ -14,11 +14,11 @@ BUILDDIR      = build
 
 # Put it first so that "make" without argument is like "make help".
 help:
-	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O) --keep-going
 
 .PHONY: help Makefile
 
 # Catch-all target: route all unknown targets to Sphinx using the new
 # "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
 %: Makefile
-	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O) --keep-going