Verify each finding against the current code and only fix it if needed.

Inline comments:
In @.github/workflows/ci.yaml:
- Around line 451-453: The argparse setup in whats_left.py is incorrectly
pre-populating args.features with default=["ssl"], so when multiple --features
are passed (from CARGO_ARGS and matrix.cargo_args) the script erroneously
includes "ssl"; update the argument definition that uses action="append" for
features to use default=None instead of default=["ssl"] (so args.features will
be None unless flags provided), and ensure any downstream logic that joins
args.features handles None appropriately (e.g., treat None as empty list) to
avoid injecting the "ssl" feature.

In `@scripts/whats_left.py`:
- Around line 70-72: The current add_argument call for the --features flag uses
action="append" with default=["ssl"], which causes the default to persist and
prevents splitting comma-separated inputs; change the add_argument for
--features to use default=None (keep action="append" or consider action="store"
depending on desired behavior), and after parsing args in the main routine
(where args is available) set args.features = ["ssl"] if args.features is None;
additionally, if you want to support comma-separated lists like "ssl,sqlite",
normalize by splitting each entry on commas and flattening/stripping them (apply
this normalization to the values collected for args.features) so --features
"ssl,sqlite" yields ["ssl","sqlite"] and providing --features overrides the
default instead of appending to it.

---

Nitpick comments:
In `@scripts/whats_left.py`:
- Around line 452-455: The code computes joined_features before checking
args.features; move the join into the conditional so you only compute and append
features when args.features is truthy (i.e., when features were actually
requested). Specifically, inside the block that tests args.features, call
",".join(args.features) and then extend cargo_build_command with ["--features",
joined_features] (referencing joined_features, args.features, and
cargo_build_command) to ensure no empty --features is added when no features are
provided and to align with the corrected default handling.