Remove reference to lead_time field (#12133)

Ref: https://github.com/inventree/InvenTree/discussions/8371#discussioncomment-17225032

docs/docs/report/context_variables.md

@@ -341,7 +341,6 @@ Each part object has access to a lot of context variables about the part. The fo
 | note | Longer form note field |
 | base_cost | Base charge added to order independent of quantity e.g. "Reeling Fee" |
 | multiple | Multiple that the part is provided in |
-| lead_time | Supplier lead time |
 | packaging | packaging that the part is supplied in, e.g. "Reel" |
 | pretty_name | The IPN, supplier name, supplier SKU and (if not null) manufacturer string joined by `|`. Ex. `P00037 | Company | 000021` |
 | unit_pricing | The price for one unit. |

src/backend/InvenTree/company/models.py

@@ -621,7 +621,6 @@ class SupplierPart(
         note: Longer form note field
         base_cost: Base charge added to order independent of quantity e.g. "Reeling Fee"
         multiple: Multiple that the part is provided in
-        lead_time: Supplier lead time
         packaging: packaging that the part is supplied in, e.g. "Reel"
         pack_quantity: Quantity of item supplied in a single pack (e.g. 30ml in a single tube)
         pack_quantity_native: Pack quantity, converted to "native" units of the referenced part