Bump FemtoVG to 0.9.0

This makes us require WebGL 2 for WASM builds, which appears to fix the use of gl.Repeat on textures (which commit 5e7ddf3 always enables now).
Otherwise images would just turn black.

Additionally, this removes one extra copy of rustybuzz.

internal/renderers/femtovg/Cargo.toml

@@ -32,7 +32,7 @@ once_cell = "1.5"
 pin-weak = "1"
 scoped-tls-hkt = "0.1"
 raw-window-handle = { version = "0.5", features = ["alloc"] }
-femtovg = { version = "0.8.0" }
+femtovg = { version = "0.9.0" }
 ttf-parser = { version = "0.20.0" } # Use the same version was femtovg's rustybuzz, to avoid duplicate crates
 unicode-script = { version = "0.5.4" } # Use the same version was femtovg's rustybuzz, to avoid duplicate crates
 imgref = { version = "1.6.1" }