ci: exclude formulas/ and evidence/ from build and e2e pipelines

These directories contain TOML process definitions and JSON evidence
files — no code changes that need testing. Also excludes docs/ and
*.md from the main CI pipeline (e2e already excluded these).

Prepares for formula and evidence PRs landing without triggering
unnecessary CI runs.

.woodpecker/e2e.yml

@@ -12,6 +12,8 @@ when:
       - "tools/**"
       - "onchain/test/FitnessEvaluator*"
       - "docs/**"
+      - "formulas/**"
+      - "evidence/**"
       - ".codeberg/**"
       - "*.md"