fix(ci): fix check-zepter PATH and cargo-audit pipefail

check-zepter: CARGO_HOME=$CI_PROJECT_DIR/.cargo but export used $HOME/.cargo/bin;
switched to $CARGO_HOME/bin so installed zepter 1.82.1 takes precedence.

cargo-audit: set -o pipefail caused the pipe to fail with cargo-audit's exit
code (1 when vulns exist) even when python check passed; redirect to file first.

.gitlab-ci.yml

@@ -103,7 +103,7 @@ check-zepter:
   script:
     - cargo metadata --format-version=1 --locked > /dev/null
     - cargo install zepter@1.82.1 --force
-    - export PATH="$HOME/.cargo/bin:$PATH"
+    - export PATH="$CARGO_HOME/bin:$PATH"
     - zepter --version
     - zepter run check
 
@@ -241,7 +241,8 @@ cargo-audit:
   before_script: []
   script:
     - cargo install cargo-audit --locked -q
-    - cargo audit --json 2>/dev/null | python3 .gitlab/check-audit.py
+    - cargo audit --json 2>/dev/null > /tmp/audit.json || true
+    - python3 .gitlab/check-audit.py < /tmp/audit.json
   allow_failure: false
   rules:
     - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH