Here's an update of nbval to the latest release. For now I didn't port 
nbdime, but simply disabled the tests that depend on it.

ok?

Index: Makefile
===================================================================
RCS file: /cvs/ports/devel/py-nbval/Makefile,v
diff -u -p -u -r1.15 Makefile
--- Makefile	29 Apr 2025 10:38:08 -0000	1.15
+++ Makefile	15 May 2025 03:44:33 -0000
@@ -1,9 +1,8 @@
 COMMENT =		py.test plugin to validate Jupyter notebooks
 
-MODPY_DISTV =	0.9.6
+MODPY_DISTV =		0.11.0
 DISTNAME =		nbval-${MODPY_DISTV}
 PKGNAME =		py-${DISTNAME}
-REVISION =		3
 
 CATEGORIES =		devel
 
@@ -15,16 +14,19 @@ MAINTAINER =		Daniel Dickman <daniel@ope
 PERMIT_PACKAGE =	Yes
 
 MODULES =		lang/python
+
 MODPY_PI =		Yes
 MODPY_PYBUILD =		setuptools
-MODPY_PYTEST_ARGS =	-v --current-env
+
+# needs port for nbdime
+MODPY_PYTEST_ARGS =	--ignore tests/test_nbdime_reporter.py
 
 RUN_DEPENDS =		devel/py-ipykernel \
 			devel/py-jupyter_client \
-			devel/py-nbformat \
-			devel/py-six \
-			devel/py-test-cov
-TEST_DEPENDS =		devel/py-nbval \
+			devel/py-nbformat
+
+TEST_DEPENDS =		${FULLPKGNAME}:${BUILD_PKGPATH} \
+			devel/py-coverage \
 			math/py-sympy
 
 .include <bsd.port.mk>
Index: distinfo
===================================================================
RCS file: /cvs/ports/devel/py-nbval/distinfo,v
diff -u -p -u -r1.3 distinfo
--- distinfo	7 Sep 2023 22:29:56 -0000	1.3
+++ distinfo	15 May 2025 03:44:33 -0000
@@ -1,2 +1,2 @@
-SHA256 (nbval-0.9.6.tar.gz) = z+/NLvZu4tM30LJSxrzsQCM4TrMui55fzDrICrjNfUA=
-SIZE (nbval-0.9.6.tar.gz) = 60932
+SHA256 (nbval-0.11.0.tar.gz) = d8lXl2B7CpaLq9JZfuNJQQLSXDrTdDXeu9rA5G43kJQ=
+SIZE (nbval-0.11.0.tar.gz) = 62718