Pass --remap-path-prefix to cargo

This is meant to reduce nondeterminism across machines or docker vs host, but it does not seem to fully
solve the problem yet (it does remove some paths from the resulting
binary, so I think it is necessary, but not sufficient).

Ref project-oak#865

scripts/common

@@ -10,6 +10,9 @@ set -o pipefail
 # https://docs.rs/env_logger
 export RUST_LOG="${RUST_LOG:-info}"
 
+# Reduce nondeterminism by remapping paths so that they don't include local path segments.
+export RUSTFLAGS="--remap-path-prefix=$PWD=/"
+
 # See https://pantheon.corp.google.com/gcr/images/oak-ci/GLOBAL/oak
 readonly DOCKER_IMAGE_NAME='gcr.io/oak-ci/oak'
 readonly SERVER_DOCKER_IMAGE_NAME='gcr.io/oak-ci/oak-server'