Widen cap-std-ext to include 2.0

Just keeping up with versions; we actually didn't use the
`rustix` re-export so we can continue to build with both
versions just to maximize flexibility for clients.

Cargo.toml

@@ -23,7 +23,8 @@ semver = "1.0.4"
 tokio = { features = ["fs", "io-util", "macros", "process", "rt", "sync"], version = "1" }
 tracing = "0.1"
 cap-tempfile = "1.0.1"
-cap-std-ext = "1.0"
+# We didn't use the rustix re-export, so we're compatible with 1.x and 2.x.
+cap-std-ext = ">= 1.0, < 3.0"
 
 [lib]
 path = "src/imageproxy.rs"