[IMP] remove references to owl template tagging

In odoo/odoo#130467 the necessity to tag owl templates with an owl="1"
attribute has been removed, update the docs to reflect that.

closes odoo/documentation#5460

Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

content/developer/tutorials/discover_js_framework/01_owl_components.rst

@@ -60,15 +60,12 @@ and defines a part of user interface:
 .. code-block:: xml
 
    <templates xml:space="preserve">
-      <t t-name="my_module.Counter" owl="1">
+      <t t-name="my_module.Counter">
          <p>Counter: <t t-esc="state.value"/></p>
          <button class="btn btn-primary" t-on-click="increment">Increment</button>
       </t>
    </templates>
 
-You maybe noticed the `owl="1"` temporary attribute, it allows Odoo to differentiate Owl
-templates from the old JavaScript framework templates. Note that Owl templates are not the same
-as QWeb templates: they can contain additional directives, such as `t-on-click`.
 
 1. Displaying a counter
 =======================

content/developer/tutorials/master_odoo_web_framework/01_fields_and_views.rst

@@ -31,7 +31,7 @@ Let us discuss a simplified implementation of a `CharField`. First, here is the
 
 .. code-block:: xml
 
-   <t t-name="web.CharField" owl="1">
+   <t t-name="web.CharField">
        <t t-if="props.readonly">
            <span t-esc="formattedValue" />
        </t>