Update reference images for PDF export progress snackbar styles.

This change includes updated binary files for the PDF export progress
snackbar, ensuring accurate visual representation during testing.

Author: shervElmi

assets/sass/vendor/_mdc-linear-progress.scss

@@ -19,7 +19,7 @@
 	}
 
 	// Animate width on the primary bar so determinate progress fills smoothly.
-	// MDC base transitions transform only.
+	// Uses MDC's sharp curve (matches the 250ms transform/opacity transitions MDC already applies to .mdc-linear-progress).
 	.mdc-linear-progress:not(.mdc-linear-progress--indeterminate) .mdc-linear-progress__primary-bar {
 		transition: width 250ms cubic-bezier(0.4, 0, 0.6, 1);
 	}