ruff

7dabc459 - Allow RUFF_NO_CACHE environment variable (like RUFF_CACHE_DIR) (#8538)

Allow RUFF_NO_CACHE environment variable (like RUFF_CACHE_DIR) (#8538) ## Summary Being able to set `--no-cache` without touching the command line makes comparing formatter speed with e.g. Hyperfine a lot easier; Black allows one to set `BLACK_CACHE_DIR=/dev/null`, but setting `RUFF_CACHE_DIR=/dev/null` has Ruff choke: ``` error: Failed to initialize cache at /dev/null: Not a directory (os error 20) error: Failed to initialize cache at /dev/null: Not a directory (os error 20) warning: Failed to open cache file '/dev/null/0.1.4/18160934645386409287': Not a directory (os error 20) ``` Alternately, we could make a `/dev/null` (or `nul` on Windows) cache directory imply `--no-cache`? ## Test Plan None yet.