ci: Add missing CI_RETRY_EXE before git clone #28623

This should fix https://github.com/bitcoin/bitcoin/actions/runs/6457002476/job/17527598426#step:7:240:

+ git clone --depth=1 https://github.com/bitcoin-core/qa-assets /Users/runner/work/bitcoin/bitcoin/ci/scratch/qa-assets
Cloning into '/Users/runner/work/bitcoin/bitcoin/ci/scratch/qa-assets'...
error: RPC failed; curl 18 HTTP/2 stream 5 was reset
error: 54975 bytes of body are still expected
fetch-pack: unexpected disconnect while reading sideband packet
fatal: early EOF
fatal: fetch-pack: invalid index-pack output
Error: Process completed with exit code 128.

<!--e57a25ab6845829454e8d69fc972939a-->

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

<!--006a51241073e994b41acfe9ec718e94-->

Code Coverage

For detailed information about the code coverage, see the test coverage report.

<!--021abf342d371248e50ceaed478a90ca-->

Reviews

See the guideline for information on the review process.

If your review is incorrectly listed, please react with 👎 to this comment and the bot will ignore it on the next update.

ACK fa84be88c3b9217fbb44b18192ceae0969d736f9, I have reviewed the code and it looks OK.

Closing due to macOS being nonsense.

Up for grabs.

Closing due to macOS being nonsense.

Up for grabs.

Done in #28643.