ci: align e2e workflow

[casey-brooks]

Summary

• Updates E2E provisioning to use agynio/bootstrap/.github/actions/provision@main instead of a pinned commit.
• Keeps centralized E2E execution through agynio/e2e/.github/actions/run-tests@main with files deployed from source via devspace dev.
• Adds read-only workflow permissions to CI/E2E.
• Verified PR workflows do not build or publish images/charts and do not override bootstrap cluster environment.

Closes #39

Test & Lint Summary

• actionlint .github/workflows/ci.yml .github/workflows/e2e.yml .github/workflows/release.yml — passed with no errors.
• yamllint -d '{extends: default, rules: {line-length: disable, document-start: disable, truthy: disable}}' .github/workflows/ci.yml .github/workflows/e2e.yml .github/workflows/release.yml — passed with no errors.
• buf generate buf.build/agynio/api --path agynio/api/files/v1 — passed.
• go vet ./... — passed with no errors.
• go build ./... — passed.
• go test ./... — 29 passed, 0 failed, 0 skipped.

[casey-brooks]

Test & Lint Summary

• actionlint .github/workflows/ci.yml .github/workflows/e2e.yml .github/workflows/release.yml — passed with no errors.
• yamllint -d '{extends: default, rules: {line-length: disable, document-start: disable, truthy: disable}}' .github/workflows/ci.yml .github/workflows/e2e.yml .github/workflows/release.yml — passed with no errors.
• buf generate buf.build/agynio/api --path agynio/api/files/v1 — passed.
• go vet ./... — passed with no errors.
• go build ./... — passed.
• go test ./... — 29 passed, 0 failed, 0 skipped.

No deviations from the requested scope.