Setting `GITHUB_TOKEN` env on `aquasecurity/trivy-action@master` did
not authenticate the github.com clone (#44 attempted that). Reason:
the action wraps `actions/checkout`, whose `with.token` input
defaults to `${{ github.token }}` (Gitea's auto-token, not our
github.com PAT), and that input wins over the GITHUB_TOKEN env
variable. The clone keeps hitting the anonymous rate limit.
Rather than chase the action's internals (INPUT_TOKEN tricks, git
config insteadOf, etc.), drop the wrapper entirely and install
Trivy directly via `curl + tar` from the GitHub release artefact.
Side benefits:
- Pinned version (`TRIVY_VERSION=0.70.0`) — no more `@master`,
which is itself an anti-pattern (moving target, surprise breaking
changes are exactly what bit us in #43).
- Predictable behaviour, fewer indirections to debug.
- GITHUBCOM_TOKEN passed as Bearer header on the curl — handles
the rate limit on release downloads as defence-in-depth (release
artefacts are usually unmetered, but the auth is free).
Trivy version bumps are now manual (Renovate cannot track this pin
out of the box). A custom regex manager in renovate.json could be
added later if the cadence justifies it; for now manual review of
https://github.com/aquasecurity/trivy/releases is fine.
Julien Gautier