Fix ABI mismatch involving Sendable-refining protocols and deployment targets

A change to the way we determined whether a protocol conformance is
"dependent" for marker protocols caused an ABI break for
Sendable-refining protocols built with pre-6.0 Swift compilers. The
fix for this issue (https://github.com/swiftlang/swift/pull/75769)
gated the change on deployment target.

The deployment target change fixed the original problem, then caused a
related issue when a project mixes deployment targets (pre-6.0 and
6.0+) with non-resilient protocols. Exempt non-resilient protocols from
this change so we get consistent behavior.

Fixes rdar://134953989.

test/Inputs/non_resilient_protocol.swift

@@ -0,0 +1,12 @@
+public protocol NonResilientSendableBase: Sendable {
+  func f()
+}
+
+public protocol NonResilientSendable: NonResilientSendableBase {
+  func g()
+}
+
+public struct ConformsToNonResilientSendable: NonResilientSendable {
+  public func f() { }
+  public func g() { }
+}