CI: reconcile lint and known unsupported corpus expectations

Simplify an equivalent slideshow bounds guard and remove an unnecessary
closure drop from an export test for strict Rust 1.95 Clippy. Include the
E-PL7 sample among known unsupported variants, matching the documented
preview-only status; retain its format and embedded-preview checks.

Generated with Codex.

crates/engine/src/slide_overlay.rs

@@ -903,7 +903,7 @@ fn shadow(img: &mut Rgba8, tl: &crate::text::TextLayout, x: f64, y: f64, sigma:
     let my0 = (y - pad).floor().max(-pad);
     let mx1 = (x + tl.width as f64 + pad).ceil().min(iw + pad);
     let my1 = (y + tl.height as f64 + pad).ceil().min(ih + pad);
-    if !(mx1 > mx0 && my1 > my0) || !mx0.is_finite() || !my0.is_finite() {
+    if !(mx1 > mx0 && my1 > my0 && mx0.is_finite() && my0.is_finite()) {
         return;
     }
     let (w, h) = ((mx1 - mx0) as usize, (my1 - my0) as usize);

crates/engine/src/tests_export.rs

@@ -1038,7 +1038,6 @@ fn same_folder_as_original_refuses_photos_without_a_folder() {
         assert_eq!(f["photo"], id.0, "{f}");
         assert!(f["error"].as_str().unwrap().contains("no folder on disk"), "{f}");
     }
-    drop(write);
     assert!(written.is_empty(), "{written:?}");
 
     // a photo on disk whose folder is gone (moved, an unplugged drive)