remove Makefile.coq.patch hack

We can achieve all desired effects without having to patch the
generated `Makefile.coq`.

Makefile

@@ -58,14 +58,18 @@ mangle-namesCoqProject: commonCoqProject
 	@find $(FIND_OPTS) \
 	  -print | scripts/module-toc-order.py >> $(COQ_PROJ)
 
-$(COQ_MAKEFILE): $(COQ_PROJ) scripts/Makefile.coq.patch
+$(COQ_MAKEFILE): $(COQ_PROJ)
 	@coq_makefile -f $< -o $@ COQDOCEXTRAFLAGS = "--parse-comments --external https://math-comp.github.io/htmldoc/ mathcomp --external mathcomp https://math-comp.github.io/htmldoc/"
-	@# Patch HTML target to switch out color.
-	@patch -s < scripts/Makefile.coq.patch
 
-install html gallinahtml htmlpretty clean cleanall validate alectryon: $(COQ_MAKEFILE)
+install htmlpretty clean cleanall validate alectryon: $(COQ_MAKEFILE)
 	$(MAKE) -f $(COQ_MAKEFILE) $@
 
+html gallinahtml: $(COQ_MAKEFILE)
+	$(MAKE) -f $(COQ_MAKEFILE) $@
+	@# Prosa hack: let's tweak the style a bit
+	@sed -i.bak "s/#90bdff/#eeeeee/" html/coqdoc.css
+	@rm html/coqdoc.css.bak
+
 %.vo: %.v
 	$(MAKE) -f $(COQ_MAKEFILE) $@
 

scripts/Makefile.coq.patch

---- Makefile.coq.orig	2021-10-04 11:15:22.592822933 +0200
-+++ Makefile.coq	2021-10-04 11:17:18.684584261 +0200
-@@ -480,6 +485,9 @@
- 	$(HIDE)mkdir -p html
- 	$(HIDE)$(COQDOC) \
- 		-toc $(COQDOCFLAGS) -html $(GAL) $(COQDOCLIBS) -d html $(VFILES)
-+# Prosa hack: let's tweak the style a bit
-+	$(HIDE)sed -i.bak "s/#90bdff/#eeeeee/" html/coqdoc.css
-+	$(HIDE)rm html/coqdoc.css.bak
- 
- mlihtml: $(MLIFILES:.mli=.cmi)
- 	$(SHOW)'CAMLDOC -d $@'