Merge bitcoin#23635: test: Bump shellcheck version to 0.8.0

5202bd1 test: Bump shellcheck version to 0.8.0 (Hennadii Stepanov)

Pull request description:

  Among [added](https://github.com/koalaman/shellcheck/blob/master/CHANGELOG.md#v080---2021-11-06) rules, SC2295 could be [useful](bitcoin#23506 (comment)) for us.

ACKs for top commit:
  dongcarl:
    Code Review ACK 5202bd1
  fanquake:
    ACK 5202bd1 - would have rather this just been a part of bitcoin#23506 to avoid another PR and pointless rebasing.

Tree-SHA512: fd7ff801c71af03c5a5b2823b7daba25a430b3ead5e5e50a3663961ee2223e55d322aec91d79999814cd35bd7ed6e9415a0b797718ceb8c0b1dbdbb40c336b82

Author: fanquake

contrib/containers/ci/ci-slim.Dockerfile

@@ -86,7 +86,7 @@ RUN set -ex; \
     cd dash_hash && pip3 install -r requirements.txt .; \
     cd .. && rm -rf dash_hash
 
-ARG SHELLCHECK_VERSION=v0.7.1
+ARG SHELLCHECK_VERSION=v0.8.0
 RUN set -ex; \
     curl -fL "https://github.com/koalaman/shellcheck/releases/download/${SHELLCHECK_VERSION}/shellcheck-${SHELLCHECK_VERSION}.linux.x86_64.tar.xz" -o /tmp/shellcheck.tar.xz; \
     mkdir -p /opt/shellcheck && tar -xf /tmp/shellcheck.tar.xz -C /opt/shellcheck --strip-components=1 && rm /tmp/shellcheck.tar.xz