Bump freetype-sys to v0.20.1 (#254)

Update freetype-sys to v0.20.1 for an OpenHarmony
build fix.

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

Author: jschwe

harfbuzz-sys/Cargo.toml

@@ -38,7 +38,7 @@ optional = true
 features = ["dwrite"]
 
 [dependencies.freetype-sys]
-version = "0.19"
+version = "0.20.1"
 optional = true
 
 [features]