Re-enable fail_ci_if_error for Codecov once upstream GPG fix ships

[blimpich]

We disabled fail_ci_if_error in .github/workflows/test.yml because Codecov's wrapper has an intermittent GPG key import failure that randomly breaks CI.

• Upstream issue: [BUG] Random fails due to uploader verification key import failing codecov/codecov-action#1876
• Upstream fix PR (pending): fix: Add retry logic and error handling for GPP key import (v0.2.8) codecov/wrapper#66 (adds retry logic, targets wrapper v0.2.8)
• Related internal issue: https://github.com/Expensify/Expensify/issues/599468

Action items

1. Monitor fix: Add retry logic and error handling for GPP key import (v0.2.8) codecov/wrapper#66 for merge/release
2. Once Codecov ships a version containing the fix, set fail_ci_if_error: true back in both codecov steps in .github/workflows/test.yml