Default file types are redundant

[epage]

❯ cargo test --lib -- --nocapture default_types::check_duplicates
    Finished test [unoptimized + debuginfo] target(s) in 0.08s
     Running unittests src/lib.rs (/home/epage/src/personal/typos/target/debug/deps/typos_cli-83a9b576bfaa71be)

running 1 test
*.conf is under multiple names: ["bitbake", "config", "systemd"]
*.el is under multiple names: ["elisp", "lisp"]
*.erb is under multiple names: ["erb", "puppet"]
*.gradle is under multiple names: ["gradle", "groovy"]
*.h is under multiple names: ["h", "objc", "objcpp", "sv"]
*.inc is under multiple names: ["bitbake", "pascal"]
*.m is under multiple names: ["matlab", "objc"]
*.mk is under multiple names: ["amake", "make"]
*.ml is under multiple names: ["ml", "ocaml"]
*.pp is under multiple names: ["pascal", "puppet"]
*.r is under multiple names: ["r", "red"]
*.rb is under multiple names: ["puppet", "ruby"]
*.scss is under multiple names: ["css", "sass"]
*.sv is under multiple names: ["sv", "verilog"]
*.svh is under multiple names: ["sv", "verilog"]
*.v is under multiple names: ["coq", "sv", "verilog"]
*.zsh is under multiple names: ["sh", "zsh"]
.zlogin is under multiple names: ["sh", "zsh"]
.zlogout is under multiple names: ["sh", "zsh"]
.zprofile is under multiple names: ["sh", "zsh"]
.zshenv is under multiple names: ["sh", "zsh"]
.zshrc is under multiple names: ["sh", "zsh"]
zlogin is under multiple names: ["sh", "zsh"]
zlogout is under multiple names: ["sh", "zsh"]
zprofile is under multiple names: ["sh", "zsh"]
zshenv is under multiple names: ["sh", "zsh"]
zshrc is under multiple names: ["sh", "zsh"]
test default_types::check_duplicates ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 50 filtered out; finished in 0.00s

[epage]

This was found when working on #911