fix: Fix de-duplication of summary sections

Author: pawamoy

src/mkdocstrings_handlers/python/templates/material/_base/summary/attributes.html.jinja

@@ -7,7 +7,7 @@
   -#}
 {% endblock logs %}
 
-{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "attributes") %}
+{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "attributes") | list %}
   {% with section = obj.attributes
       |filter_objects(
         filters=config.filters,

src/mkdocstrings_handlers/python/templates/material/_base/summary/classes.html.jinja

@@ -7,7 +7,7 @@
   -#}
 {% endblock logs %}
 
-{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "classes") %}
+{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "classes") | list %}
   {% with section = obj.classes
       |filter_objects(
         filters=config.filters,

src/mkdocstrings_handlers/python/templates/material/_base/summary/functions.html.jinja

@@ -7,7 +7,7 @@
   -#}
 {% endblock logs %}
 
-{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "functions") %}
+{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "functions") | list %}
   {% with section = obj.functions
       |filter_objects(
         filters=config.filters,

src/mkdocstrings_handlers/python/templates/material/_base/summary/modules.html.jinja

@@ -7,7 +7,7 @@
   -#}
 {% endblock logs %}
 
-{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "modules") %}
+{% if not obj.docstring.parsed | selectattr("kind.value", "eq", "modules") | list %}
   {% with section = obj.modules
       |filter_objects(
         filters=config.filters,