How did 'seasoning' semantically shift to mean "heating fat or oil on a cooking vessel's surface to coat it resistantly to corrosion and stick'?

The OED doesn't comprise this definition. The closest appears to be:

[1] c. The maturing of wood by drying, etc.; †also, tempering, hardening (of metals).

i. The application of a solution of blood and logwood to leather prior to blacking. Also attributive.

j. The application of one of various finishes to leather after tanning.

How to: Cleaning and Seasoning a Cast-Iron Skillet | Cook It In Cast Iron

The Science of Seasoning

When fat or cooking oil is heated for a long enough time in cast iron, its fatty acids oxidize and reorganize together (or “polymerize”) into a new plastic-like layer of molecules. This layer becomes trapped within the pitted surface of the pan and bonds to the metal itself, creating the slick coating known as seasoning. Repeated exposure to hot oil continues to build on this coating, making it more slippery and durable. That’s why even though most skillets these days come with a factory seasoning, the surface will become even more nonstick with repeated use.

Solution 1:

The OED doesn't comprise this definition.

It does...

OED

4.a. To bring to maturity, ripen; to render fit for use by prolonged exposure to atmospheric influences, or by gradual subjection to conditions of the kind to be undergone in actual working; often, to dry and harden (timber) by long keeping.

1555 R. Eden tr. Peter Martyr of Angleria Decades of Newe Worlde i. ix. f. 43 They browght with them Cinamome and gynger: but not very good, bycause they were not there fully seasoned with the heate of the soone. (Modern English - They brought with them cinnamon and ginger: but not very good, because they had not been fully seasoned by the heat of the sun there.)

1686 R. Plot Nat. Hist. Staffs. iv. 161 They also heat their furnace for a weeks time with charcoal without blowing it, which they call seasoning it.

1858 O. W. Holmes Autocrat of Breakfast-table vi. 154 Knowledge and timber shouldn't be much used till they are seasoned.

Note the 1686 quote which has parallels with your frying pan and also "to render fit for use [...] by gradual subjection to conditions of the kind to be undergone in actual working