fix: unpin kani-verifier version in Dockerfile

Remove the pin of kani to 0.45.0.

We introduced this pin in 2f01981 due
to model-checking/kani#3035. Kani fixed the
issue in 0.48.0 (verifier by installing kani 0.48.0 locally and
executing the gcd proof), so we can remove the pin and pick up a new
kani version the next time we rebuild the docker container.

Signed-off-by: Patrick Roy <roypat@amazon.co.uk>

tools/devctr/Dockerfile

@@ -111,7 +111,7 @@ RUN curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain "$RUST_TOOL
     && rustup target add aarch64-unknown-linux-musl \
     && rustup component add llvm-tools-preview \
     && cargo install --locked cargo-audit cargo-deny grcov cargo-sort \
-    && (if [ "$ARCH" = "x86_64" ]; then cargo install --locked kani-verifier --version 0.45.0 && cargo kani setup; else true; fi) \
+    && (if [ "$ARCH" = "x86_64" ]; then cargo install --locked kani-verifier && cargo kani setup; else true; fi) \
     \
     && apt-get update \
     && apt-get -y install --no-install-recommends \