dev-haskell/linear: remove unused local USE from metadata.xml

Signed-off-by: Jack Todaro <solpeth@posteo.org>
Closes: #26672
Signed-off-by: Sam James <sam@gentoo.org>

dev-haskell/linear/metadata.xml

@@ -5,14 +5,6 @@
 		<email>haskell@gentoo.org</email>
 		<name>Gentoo Haskell</name>
 	</maintainer>
-	<use>
-		<flag name="template-haskell">
-			You can disable the use of the
-			`template-haskell` package using `-f-template-haskell`. Disabling this is an
-			unsupported configuration, but it may be useful for accelerating builds in
-			sandboxes for expert users.
-		</flag>
-	</use>
 	<upstream>
 		<remote-id type="github">ekmett/linear</remote-id>
 	</upstream>