refactor(eslint): fix eslint warnings in manager (#4865)

lib/manager/buildkite/extract.ts

lib/manager/bundler/extract.ts

lib/manager/cargo/artifacts.ts

lib/manager/cargo/extract.ts

lib/manager/composer/extract.ts

lib/manager/gradle-wrapper/update.ts

lib/manager/gradle/build-gradle.ts

lib/manager/gradle/gradle-updates-report.ts

lib/manager/gradle/index.ts

lib/manager/helm-requirements/update.ts

lib/manager/homebrew/extract.ts

lib/manager/homebrew/update.ts

lib/manager/homebrew/util.ts

lib/manager/index.ts

lib/manager/leiningen/extract.ts

lib/manager/maven/extract.ts

lib/manager/mix/artifacts.ts

lib/manager/npm/extract/index.ts

lib/manager/npm/extract/locked-versions.ts

lib/manager/npm/extract/monorepo.ts