[FIX] tools: remove max language length constraint

There is no reason for this constraint to be. Languages with a code
longer than 5 do exists in standard, (e.g. ar_001, sr@latin)

Introduced at 004a0b99

Fixes odoo/odoo#52558

closes odoo/odoo#52569

X-original-commit: 54340487
Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>