gbuild: Drop obsolete checks for make version 3.81

make 3.81 is no more suppoprted, see

    commit 4688e74bcf
    Date:   Fri Apr 8 11:22:27 2022 +0200

        configure: require GNU make 3.82

Change-Id: I0f820512df96fa1712374d3308d15591799222fa
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/133592
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

solenv/Module_solenv.mk

@@ -29,7 +29,6 @@ $(eval $(call gb_Module_add_targets,solenv,\
 endif
 
 ifneq ($(DISABLE_PYTHON),TRUE)
-ifneq ($(MAKE_VERSION),3.81) # gbuildtojson requires 3.82+
 ifneq ($(OS),WNT) # disable on Windows for now, causes gerrit/jenkins failures
 ifneq ($(OS),MACOSX) # disable on macOS too, fails at least for me and would be pointless anyway surely
 $(eval $(call gb_Module_add_subsequentcheck_targets,solenv,\
@@ -39,7 +38,6 @@ $(eval $(call gb_Module_add_subsequentcheck_targets,solenv,\
 endif
 endif
 endif
-endif
 
 ifneq ($(COMPILER_PLUGINS),)
 ifeq ($(COMPILER_EXTERNAL_TOOL)$(COMPILER_PLUGIN_TOOL),)

solenv/gbuild/extensions/post_GbuildToJson.mk

@@ -24,10 +24,6 @@
 
 ifneq ($(filter gbuildtojson,$(MAKECMDGOALS)),)
 
-ifeq ($(MAKE_VERSION),3.81)
-$(error make version 3.81 not supported for gbuildtojson; install newer make via LODE)
-endif
-
 # possibly recurse to ensure gbuildtojson was build before running the modded make
 gb_GbuildToJson_prep := $(shell $(MAKE) -f $(SRCDIR)/solenv/Makefile Executable_gbuildtojson)
 gb_FULLDEPS:=