update warning filters in tox

tox.ini

@@ -274,8 +274,7 @@ commands_pre =
     pip install -r {env_tmp_dir}/requirements.txt
     pip freeze
 commands =
-    pytest roman_datamodels/tests \
-        -W "ignore:asdf.extensions plugin from package gwcs==0.18.3:asdf.exceptions.AsdfWarning"
+    pytest roman_datamodels/tests
 
 [testenv:weldx]
 change_dir = {env_tmp_dir}
@@ -320,5 +319,8 @@ commands_pre =
     pip install -r {env_tmp_dir}/requirements.txt
     pip freeze
 commands =
+# the AsdfManifestURIMismatchWarning filter can be removed when a new sunpy
+# is released which contains the fixed manifests:
+# https://github.com/sunpy/sunpy/pull/7432
     pytest dkist \
-        -W "ignore:asdf.extensions plugin from package gwcs==0.18.3:asdf.exceptions.AsdfWarning"
+        -W "ignore::asdf.exceptions.AsdfManifestURIMismatchWarning"