ci: fix test job not caching anything.

.github/ci/build-stable.sh

@@ -27,4 +27,4 @@ sed -i 's/channel.*/channel = "beta"/g' rust-toolchain.toml
 
 # Save lockfiles
 echo Saving lockfiles...
-find . -type f -name Cargo.lock -exec tar -cf /ci/cache/lockfiles.tar '{}' \+
+find . -type f -name Cargo.lock -exec tar -cf /ci/cache/lockfiles.tar '{}' \+

.github/ci/build.sh

@@ -31,4 +31,4 @@ hashtime save /ci/cache/filetime.json
 
 # Save lockfiles
 echo Saving lockfiles...
-find . -type f -name Cargo.lock -exec tar -cf /ci/cache/lockfiles.tar '{}' \+
+find . -type f -name Cargo.lock -exec tar -cf /ci/cache/lockfiles.tar '{}' \+

.github/ci/crlf.sh

@@ -14,4 +14,4 @@ else
   echo -e "ERROR: Found ${NR_FILES} files with CRLF endings."
   echo "$FILES_WITH_CRLF"
   exit "$NR_FILES"
-fi
+fi

.github/ci/test.sh

@@ -4,6 +4,10 @@
 
 set -euo pipefail
 
+export RUSTUP_HOME=/ci/cache/rustup
+export CARGO_HOME=/ci/cache/cargo
+export CARGO_TARGET_DIR=/ci/cache/target
+
 MIRIFLAGS=-Zmiri-ignore-leaks cargo miri test --manifest-path ./embassy-executor/Cargo.toml
 MIRIFLAGS=-Zmiri-ignore-leaks cargo miri test --manifest-path ./embassy-executor/Cargo.toml --features nightly