docs: Update fd.o spec URLs

This wasn't strictly needed, since all of them have redirects, but it's
still nicer and guarantees the anchors are also honoured (as we couldn't
set up redirects for those).

docs/xml/catalog-xmldata.xml

@@ -307,7 +307,7 @@
 					</para>
 					<para>
 						If specified, the <literal>scale</literal> property is defined as in the
-						<ulink url="https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html#definitions">Freedesktop Icon Theme Specification</ulink>.
+						<ulink url="https://specifications.freedesktop.org/icon-theme-spec/latest/#definitions">Freedesktop Icon Theme Specification</ulink>.
 						It’s an integer value ≥1 indicating how many pixels in the image represent a logical pixel on the display, in each dimension.
 						This allows icons for hi-DPI screens to be displayed at the same logical size as on lower resolution screens, but without upscaling artifacts.
 					</para>
@@ -339,7 +339,7 @@
 						This tag can contain one or more <code><![CDATA[<category>]]></code> tags, describing the categories this component
 						is located in. This tag is usually applied to components of type <literal>desktop-application</literal>, although it might be used by others later.
 						This data is usually taken from Desktop files, a list of categories can be found in the
-						<ulink url="https://standards.freedesktop.org/menu-spec/latest/apa.html">Freedesktop menu spec</ulink>.
+						<ulink url="https://specifications.freedesktop.org/menu-spec/latest/category-registry.html">Freedesktop menu spec</ulink>.
 						Example:
 					</para>
 					<programlisting language="XML"><![CDATA[<categories>

docs/xml/metainfo-component.xml

@@ -273,7 +273,7 @@
 						is associated with.
 						This tag is usually applied to components of type <literal>desktop-application</literal>, but can be used with any component.
 						A list of valid category names can be found in the
-						<ulink url="https://specifications.freedesktop.org/menu-spec/latest/apa.html">Freedesktop menu specification</ulink>.
+						<ulink url="https://specifications.freedesktop.org/menu-spec/latest/category-registry.html">Freedesktop menu specification</ulink>.
 						Example:
 					</para>
 					<programlisting language="XML"><![CDATA[<categories>
@@ -424,7 +424,7 @@
                     <listitem>
                       <para>
                         The application can be launched via a desktop file. The value of the tag is a
-			<ulink url="https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#desktop-file-id">desktop-file id</ulink>.
+			<ulink url="https://specifications.freedesktop.org/desktop-entry-spec/latest/file-naming.html#desktop-file-id">desktop-file id</ulink>.
                       </para>
                       <para>
                         In case a software component has multiple launchable entries,
@@ -1114,7 +1114,7 @@
 				The distributor decides which components should be made compulsory, however it is generally a good idea to follow upstream's recommendations on that matter.
 			</para>
 			<para>
-				A list of all allowed values for this tag is defined in the <ulink url="https://specifications.freedesktop.org/menu-spec/latest/apb.html">XDG Menu Specification</ulink>.
+				A list of all allowed values for this tag is defined in the <ulink url="https://specifications.freedesktop.org/menu-spec/latest/onlyshowin-registry.html">XDG Menu Specification</ulink>.
 				Software center applications will only recognize these values.
 			</para>
 		</listitem>