chore: fix the release tag discovering in the release CI job

[greenhat]

Close #954

Fix explanation

The RELEASES env var during the job run https://github.com/0xMiden/compiler/actions/runs/21938641353/job/63359786464 was:

[
...
  {
    "package_name": "cargo-miden",
    "prs": [],
    "tag": "0.7.0",
    "version": "0.7.0"
  }
]

And in the release-plz.toml we have

compiler/release-plz.toml

Line 20 in f66b8d9

git_tag_name = "{{ version }}"