Fix setup-task version hints

[rdimitrov]

Summary

• Renovate cannot resolve the pinned arduino/setup-task action because its # v2 hint refers to an upstream branch rather than a tag, leaving a persistent package lookup warning in the dependency dashboard.
• Update all 12 hints across seven workflows to the exact v2.0.0 tag, which resolves to the already-pinned commit and therefore does not change CI execution.

Related: #561

Type of change

• Bug fix
• New feature
• Refactoring (no behavior change)
• Dependency update
• Documentation
• Other (describe):

Test plan

• Unit tests (task test)
• E2E tests (task test-e2e)
• Linting (task lint-fix)
• Manual testing (describe below)

Ran Renovate 44.71.2 locally in lookup mode with GitHub authentication. Renovate resolved all 12 arduino/setup-task references as v2.0.0, continued to detect the separate v3 major update, and no longer emitted the Could not determine new digest warning for this action.

Changes

File	Change
Seven GitHub Actions workflow files	Replace # v2 with the exact # v2.0.0 tag on all 12 pinned arduino/setup-task references

Does this introduce a user-facing change?

No.

Implementation plan

Approved implementation plan

Update only the version hints, retain the existing immutable SHA pins, verify the warning disappears with a full Renovate lookup, and keep the v3 action upgrade as a separate compatibility change.

Special notes for reviewers

Issue #561 is Renovate's long-lived dependency dashboard, so this PR references it without closing it.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.79%. Comparing base (71e8e50) to head (3388415).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6565      +/-   ##
==========================================
+ Coverage   78.72%   78.79%   +0.07%     
==========================================
  Files         777      778       +1     
  Lines       77213    77490     +277     
==========================================
+ Hits        60784    61058     +274     
- Misses      16424    16427       +3     
  Partials        5        5              

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