appdata: Remove none OARS tags

"The old generator also included all the none-value entries—it
no longer does this, you can safely remove them.

If it only consists of none values, it’s safe to shorten it to just:
`<content_rating type="oars-1.1" />`"

More information: https://docs.flathub.org/docs/for-app-authors/appdata-guidelines/#oars-information

data/com.github.tenderowl.frog.appdata.xml.in

@@ -159,33 +159,5 @@
     <url type="donation">https://www.buymeacoffee.com/tenderowl/</url>
     <update_contact>andrey@tenderowl.com</update_contact>
 
-    <content_rating type="oars-1.1">
-        <content_attribute id="violence-cartoon">none</content_attribute>
-        <content_attribute id="violence-fantasy">none</content_attribute>
-        <content_attribute id="violence-realistic">none</content_attribute>
-        <content_attribute id="violence-bloodshed">none</content_attribute>
-        <content_attribute id="violence-sexual">none</content_attribute>
-        <content_attribute id="violence-desecration">none</content_attribute>
-        <content_attribute id="violence-slavery">none</content_attribute>
-        <content_attribute id="violence-worship">none</content_attribute>
-        <content_attribute id="drugs-alcohol">none</content_attribute>
-        <content_attribute id="drugs-narcotics">none</content_attribute>
-        <content_attribute id="drugs-tobacco">none</content_attribute>
-        <content_attribute id="sex-nudity">none</content_attribute>
-        <content_attribute id="sex-themes">none</content_attribute>
-        <content_attribute id="sex-homosexuality">none</content_attribute>
-        <content_attribute id="sex-prostitution">none</content_attribute>
-        <content_attribute id="sex-adultery">none</content_attribute>
-        <content_attribute id="sex-appearance">none</content_attribute>
-        <content_attribute id="language-profanity">none</content_attribute>
-        <content_attribute id="language-humor">none</content_attribute>
-        <content_attribute id="language-discrimination">none</content_attribute>
-        <content_attribute id="social-chat">none</content_attribute>
-        <content_attribute id="social-info">none</content_attribute>
-        <content_attribute id="social-audio">none</content_attribute>
-        <content_attribute id="social-location">none</content_attribute>
-        <content_attribute id="social-contacts">none</content_attribute>
-        <content_attribute id="money-purchasing">none</content_attribute>
-        <content_attribute id="money-gambling">none</content_attribute>
-    </content_rating>
+    <content_rating type="oars-1.1" />
 </component>