Revert "Introduce static features"

This reverts commit c9b6db5.

Suggested in Fedora Linux package review:

https://bugzilla.redhat.com/show_bug.cgi?id=2249863#c4

Author: musicinmybrain

Diff for: Cargo.toml

@@ -21,7 +21,3 @@ lz4-sys = { path = "lz4-sys", version = "1.9.4" }
 [dev-dependencies]
 rand = ">=0.7, <=0.8"
 docmatic = "0.1"
-
-[features]
-# Enable this feature if you want to have a statically linked liblz4
-static = ["lz4-sys/static"]

Diff for: lz4-sys/Cargo.toml

@@ -14,7 +14,3 @@ libc = "0.2.44"
 [build-dependencies]
 cc = "1.0.25"
 pkg-config = "0.3.9"
-
-[features]
-# Enable this feature if you want to have a statically linked liblz4
-static = []

Diff for: lz4-sys/build.rs

@@ -18,7 +18,6 @@ fn run() -> Result<(), Box<dyn Error>> {
     let target = get_from_env("TARGET")?;
 
     if !target.contains("windows")
-        && !cfg!(feature = "static")
         && pkg_config::Config::new()
             .print_system_libs(false)
             .cargo_metadata(true)