Don't pass the default version in DEPENDS_ARGS.

This greatly simplifies handling for Poudriere.

With hat:	portmgr

Mk/Uses/python.mk

@@ -377,7 +377,8 @@ IGNORE=		needs an unsupported version of Python
 # try to find a different one, if the passed version fits into
 # the supported version range.
 PYTHON_VERSION?=	python${_PYTHON_VERSION}
-.if !defined(PYTHON_NO_DEPENDS)
+.if !defined(PYTHON_NO_DEPENDS) && \
+    ${PYTHON_VERSION} != ${PYTHON_DEFAULT_VERSION}
 DEPENDS_ARGS+=		PYTHON_VERSION=${PYTHON_VERSION}
 .endif
 

Mk/bsd.ruby.mk

@@ -256,7 +256,9 @@ RUBY_SHLIBVER?=		${RUBY_VER:S/.//}
 
 RUBY_CONFIGURE_ARGS+=	--program-prefix=""
 
+.if ${RUBY_VER} != ${RUBY_DEFAULT_VER}
 DEPENDS_ARGS+=		RUBY_VER=${RUBY_VER}
+.endif
 
 RUBY_CONFIGURE_ARGS+=	--program-suffix="${RUBY_SUFFIX}"