Fixes #21213: Make Tag weight field required in forms (#21218)
The weight field was explicitly declared with required=False in TagForm
and TagImportForm, allowing empty submissions that would crash with a
database IntegrityError since the column is NOT NULL.
By removing the explicit field override, Django now auto-generates the
form field from the model, which has default=1000 and is required.
Co-authored-by: adionit7 <adionit7@users.noreply.github.com>