[security risk] zizmor output: sanitization step needed in sigstore step of our publish pypi build

[lwasser]

I ran zizmor on our pyosMeta publish-pypi build and found some issues. i think the biggest one is we can sanitize the branch name in our sigstore step!! 🚀 there are some other token related items that i'm not sure about.

luckily no one uses our package besides us but it can't hurt to clean things up!

➜ zizmor .github/workflows/publish-pypi.yml 
2024-12-19T03:38:13.605225Z  WARN zizmor: skipping impostor-commit: can't run without a GitHub API token
2024-12-19T03:38:13.605258Z  WARN zizmor: skipping ref-confusion: can't run without a GitHub API token
2024-12-19T03:38:13.605264Z  WARN zizmor: skipping known-vulnerable-actions: can't run without a GitHub API token
2024-12-19T03:38:13.607075Z  INFO audit: zizmor: 🌈 completed /Users/leahawasser/Documents/GitHub/pyos/pyosMeta/.github/workflows/publish-pypi.yml
warning[artipacked]: credential persistence through GitHub Actions artifacts
  --> /Users/leahawasser/Documents/GitHub/pyos/pyosMeta/.github/workflows/publish-pypi.yml:18:9
   |
18 |         - name: Checkout
   |  _________-
19 | |         uses: actions/checkout@v4
...  |
24 | |
25 | |       # Need the tags so that setuptools-scm can form a valid version number
   | |____________________________________________________________________________- does not set persist-credentials: false
   |
   = note: audit confidence → Low

error[template-injection]: code injection via template expansion
   --> /Users/leahawasser/Documents/GitHub/pyos/pyosMeta/.github/workflows/publish-pypi.yml:97:7
    |
 97 |       - name: Upload artifact signatures to GitHub Release
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this step
 98 |         env:
...
102 |         # sigstore-produced signatures and certificates.
103 | /       run: >-
104 | |         gh release upload
105 | |         '${{ github.ref_name }}' dist/**
106 | |         --repo '${{ github.repository }}'
    | |__________________________________________^ github.ref_name may expand into attacker-controllable code
    |
    = note: audit confidence → High

9 findings (7 suppressed): 0 unknown, 0 informational, 0 low, 1 medium, 1 high