fix(regex): don’t escape forward slash in fileMatch (#19314)

docs/usage/configuration-options.md

lib/config/options/index.ts

lib/config/presets/internal/group.ts

lib/config/presets/internal/monorepo.ts

lib/modules/datasource/deno/index.ts

lib/modules/datasource/go/releases-goproxy.ts

lib/modules/datasource/hermit/index.ts

lib/modules/datasource/maven/index.ts

lib/modules/datasource/pypi/common.ts

lib/modules/manager/bazelisk/index.ts

lib/modules/manager/cocoapods/extract.ts

lib/modules/manager/flux/common.ts

lib/modules/manager/fvm/index.ts

lib/modules/manager/github-actions/index.ts

lib/modules/manager/gitlabci/utils.ts

lib/modules/manager/gradle/index.ts

lib/modules/manager/mint/index.ts

lib/modules/manager/nix/index.ts

lib/modules/manager/nuget/index.ts

lib/modules/manager/pre-commit/extract.ts