Temporarily use 1.65 toolchain

Temporarily explicitly use this version due to a compiler bug:

See: rust-lang/rust#108970

Author: wiktor-k

ci/build.dockerfile

@@ -1,4 +1,6 @@
-FROM rust
+# Temporarily explicitly use this version due to a compiler bug:
+# https://github.com/rust-lang/rust/issues/108970
+FROM rust:1.65
 
 RUN apt-get update -y -qq && \
     apt-get install -y -qq --no-install-recommends python3 python3-venv clang make pkg-config nettle-dev libssl-dev ca-certificates pip pcscd libpcsclite-dev codespell && \