textproc/py-pygments is no longer compatible with python27 so add a PY_PYGMENTS variable

With hat:	portmgr

Mk/Uses/python.mk

@@ -638,10 +638,12 @@ PYNUMPY=	${PYTHON_PKGNAMEPREFIX}numpy>=1.16,1<1.20,1:math/py-numpy@${PY_FLAVOR}
 # Common Python modules that can be needed but only for some versions of Python.
 .if ${PYTHON_REL} < 3500
 PY_PILLOW=	${PYTHON_PKGNAMEPREFIX}pillow6>=6.0.0:graphics/py-pillow6@${PY_FLAVOR}
+PY_PYGMENTS=	${PYTHON_PKGNAMEPREFIX}pygments-25>=0:textproc/py-pygments-25@${PY_FLAVOR}
 PY_SPHINX=	${PYTHON_PKGNAMEPREFIX}sphinx18>=0:textproc/py-sphinx18@${PY_FLAVOR}
 PY_TYPING=	${PYTHON_PKGNAMEPREFIX}typing>=3.7.4.1:devel/py-typing@${PY_FLAVOR}
 .else
 PY_PILLOW=	${PYTHON_PKGNAMEPREFIX}pillow>=7.0.0:graphics/py-pillow@${PY_FLAVOR}
+PY_PYGMENTS=	${PYTHON_PKGNAMEPREFIX}pygments>=0:textproc/py-pygments@${PY_FLAVOR}
 PY_SPHINX=	${PYTHON_PKGNAMEPREFIX}sphinx>=0:textproc/py-sphinx@${PY_FLAVOR}
 PY_TYPING=
 .endif