globset: add opt-in Arbitrary trait implementations

This feature is mandatory when using `Glob` in fuzz testing.

Closes #2720

ci/ubuntu-install-packages

@@ -11,4 +11,4 @@ if ! command -V sudo; then
 fi
 sudo apt-get update
 sudo apt-get install -y --no-install-recommends \
-  zsh xz-utils liblz4-tool musl-tools brotli zstd
+  zsh xz-utils liblz4-tool musl-tools brotli zstd g++