[libjulia] correct soname to use only major version number (JuliaLang…

…#38748)

The soname was changed in JuliaLang#38160 to be libjulia.so.1.6 instead of
libjulia.so.1, but probably not on purpose.

This contradicts what is written in the comment in Make.inc and it breaks
e.g. libcxxwrap_julia_jll which is linked against libjulia.so.1.
See JuliaPackaging/Yggdrasil#2233

cli/Makefile

@@ -114,7 +114,7 @@ endef
 endif
 
 $(build_shlibdir)/libjulia.$(JL_MAJOR_MINOR_SHLIB_EXT): $(LIB_OBJS) | $(build_shlibdir) $(build_libdir)
-	@$(call PRINT_LINK, $(CC) $(call IMPLIB_FLAGS,$@) $(LOADER_CFLAGS) -DLIBRARY_EXPORTS -shared $(SHIPFLAGS) $(LIB_OBJS) -o $@ $(LOADER_LDFLAGS) $(RPATH_LIB)) $(call SONAME_FLAGS,$(notdir $@))
+	@$(call PRINT_LINK, $(CC) $(call IMPLIB_FLAGS,$@) $(LOADER_CFLAGS) -DLIBRARY_EXPORTS -shared $(SHIPFLAGS) $(LIB_OBJS) -o $@ $(LOADER_LDFLAGS) $(RPATH_LIB)) $(call SONAME_FLAGS,libjulia.$(JL_MAJOR_SHLIB_EXT))
 	$(INSTALL_NAME_CMD)libjulia.$(SHLIB_EXT) $@
 ifneq ($(OS), WINNT)
 	@ln -sf $(notdir $@) $(build_shlibdir)/libjulia.$(JL_MAJOR_SHLIB_EXT)