Tkinter: `Tkapp_CallDeallocArgs()` should be `static`

[chrstphrchvz]

…as per PEP 7.

Linked PRs

• gh-112678: Declare Tkapp_CallDeallocArgs() as static #112679
• [3.12] gh-112678: Declare Tkapp_CallDeallocArgs() as static (GH-112679) #112690
• [3.11] gh-112678: Declare Tkapp_CallDeallocArgs() as static (GH-112679) #112691

[serhiy-storchaka]

Good catch!