Remove unused regex dep from bevy_render (bevyengine#9613)

# Objective

As far as I can tell, this is no longer needed since the switch to
fancier shader imports via `naga_oil`.

This shouldn't have any affect on compile times because it's in our tree
from `naga_oil`, `tracing-subscriber`, and `rodio`.

crates/bevy_render/Cargo.toml

@@ -71,7 +71,6 @@ futures-lite = "1.4.0"
 anyhow = "1.0"
 hexasphere = "9.0"
 parking_lot = "0.12.1"
-regex = "1.5"
 ddsfile = { version = "0.5.0", optional = true }
 ktx2 = { version = "0.3.0", optional = true }
 naga_oil = "0.8"