Remove redundant ghp-import recipe

It was already being installed via requirements.txt

Makefile

@@ -85,6 +85,10 @@ stopserver: | venv
 publish: | venv
 	$(PELICAN) $(INPUTDIR) -o $(OUTPUTDIR) -s $(PUBLISHCONF) $(PELICANOPTS)
 
+github: submodule publish | venv
+	$(VENV)/ghp-import -m "Generate Pelican site" -b $(GITHUB_PAGES_BRANCH) $(OUTPUTDIR)
+	git push origin $(GITHUB_PAGES_BRANCH)
+
 .PHONY: html help clean regenerate serve serve-global devserver publish ssh_upload rsync_upload dropbox_upload ftp_upload s3_upload cf_upload github
 
 
@@ -99,10 +103,3 @@ Makefile.venv:
 		&& mv Makefile.fetched Makefile.venv
 VENVDIR:=$(abspath $(VENVDIR))
 export PELICAN
-
-$(VENV)/ghp-import:
-	$(VENV)/pip install ghp-import
-
-github: submodule publish $(VENV)/ghp-import
-	$(VENV)/ghp-import -m "Generate Pelican site" -b $(GITHUB_PAGES_BRANCH) $(OUTPUTDIR)
-	git push origin $(GITHUB_PAGES_BRANCH)