cargo: Bump bindgen dependency version

[CohenArthur]

The current bindgen version used by the module is 0.25
Sadly, this means that bindgen relies on aster, a deprecated crate relying on an old version of syntex_syntax. Currently, the module (and other plugins depending on it, such as https://github.com/Geal/rust-vlc-demux, do not build

error[E0423]: expected function, tuple struct or tuple variant, found struct `ast::Name`
   --> /home/kagounard/.cargo/registry/src/github.heygears.com-1ecc6299db9ec823/syntex_syntax-0.58.1/src/symbol.rs:146:27
    |
146 |                       name: ast::Name($index),
    |                             ^^^^^^^^^
...
165 | / declare_keywords! {
166 | |     // Invalid identifier
167 | |     (0,  Invalid,        "")
168 | |
...   |
231 | |     (56, CrateRoot, "{{root}}")
232 | | }
    | |_- in this macro invocation
    |
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

Extrait of cargo tree:

> cargo tree 
vlc_module v0.1.0
└── libc v0.2.91
[build-dependencies]
└── bindgen v0.25.5
    ├── aster v0.41.0
    │   └── syntex_syntax v0.58.1

bindgen has since moved on from aster in later versions