Make unsplit variants of Cyrillic Lower Ef and non-cursive variants of Greek Lower Phi use SmallArchDepth{A|B}.

[jmcwilliams403]

Basically further parity with the conventions of existing letters, much like the prior PR's of #2590 and #2602 , and made easier to implement via #2645 .

ΦϕФф

Thin Upright Before:

Thin Upright After:

Regular Upright Before:

Regular Upright After:

Heavy Upright Before:

Heavy Upright After:

Thin Italic Before:

Thin Italic After:

Regular Italic Before:

Regular Italic After:

Heavy Italic Before:

Heavy Italic After:

Stress test under Aile under SS03:
ΦϕФфo
Thin Upright:

Regular Upright:

Heavy Upright:

Thin Italic:

Regular Italic:

Heavy Italic: