chore: disable printpdf default features (unused html deps)

printpdf's default = ["html"] pulled in azul-layout, rust-fontconfig,
kuchiki, xmlparser and their transitive trees (~40+ crates including
two with cdylib targets) — none of which are used by the project's
PDF export (only basic primitives like Mm, Line, Polygon, Rgb).

Also fixes a MinGW linker error (export ordinal too large: 100035)
triggered when ld.bfd tries to build a DLL for printpdf with >65535
exported symbols.

Cargo.toml

@@ -87,7 +87,7 @@ rayon = "1"
 open = "5"
 # PDF export / printing. Native-only: printpdf pulls a wasm-incompatible
 # `memchr` (1.0.2) via lopdf → nom_locate, and the web build has no filesystem.
-printpdf = "0.9.1"
+printpdf = { version = "0.9.1", default-features = false }
 ureq = { version = "3", default-features = false, features = ["rustls"] }
 # Parse the GitHub Releases API response for the plugin marketplace.
 serde_json = "1"