chore: remove all gitFs references (#3807)

lib/config/definitions.js

lib/config/migration.js

lib/manager/bundler/artifacts.js

lib/manager/cargo/artifacts.js

lib/manager/composer/artifacts.js

lib/manager/gomod/artifacts.js

lib/manager/gradle/index.js

lib/manager/pip_setup/extract.js

lib/manager/pipenv/artifacts.js

lib/platform/azure/index.js

lib/platform/bitbucket-server/index.ts

lib/platform/bitbucket/index.ts

lib/platform/git/storage.ts

lib/platform/github/index.js

lib/platform/gitlab/index.js

renovate-schema.json

test/config/__snapshots__/migration.spec.js.snap

test/manager/cargo/artifacts.spec.js

test/manager/composer/artifacts.spec.js

test/manager/gomod/artifacts.spec.js