chore(search): drop the dead legacy tika key

services/search/pkg/content/tika_motion_photo.go

@@ -90,8 +90,7 @@ func motionPhotoVideoSize(meta map[string][]string) (int64, bool) {
 // really there, so its presence is what confirms the facet: a shared motion
 // photo can keep the xmp and lose the appended video.
 func isMotionPhotoVideo(meta map[string][]string) bool {
-	// tika 4 renamed the meta prefix from X-TIKA: to tk:
-	name, err := getFirstValue(meta, "tk:resource-name", "X-TIKA:resource-name")
+	name, err := getFirstValue(meta, "tk:resource-name")
 	if err != nil {
 		return false
 	}

services/search/pkg/content/tika_motion_photo_test.go

@@ -83,7 +83,6 @@ var _ = Describe("isMotionPhotoVideo", func() {
 			Expect(isMotionPhotoVideo(meta)).To(Equal(expected))
 		},
 		Entry("named attachment", map[string][]string{"tk:resource-name": {"motion-photo.mp4"}}, true),
-		Entry("legacy tika prefix", map[string][]string{"X-TIKA:resource-name": {"motion-photo.mp4"}}, true),
 		Entry("no extension, as for MicroVideo", map[string][]string{"tk:resource-name": {"motion-photo"}}, true),
 		Entry("another attachment", map[string][]string{"tk:resource-name": {"cover.jpg"}}, false),
 		Entry("a name that only starts alike", map[string][]string{"tk:resource-name": {"motion-photography.mp4"}}, false),