Tests: Canary Swift Testing test (#8267)

Add a canary swift testing tests to ensure we do not regress.

This test will be removed sometime after #8092, #8093 or #8100 are
merged

(cherry picked from commit 257e671)

Re-adds #8222, after it was reverted in #8266 
Depends on swiftlang/swift#79074

Author: bkhouri

Tests/BasicsTests/SampleTests.swift

@@ -0,0 +1,9 @@
+import Testing
+
+struct Foo {
+
+    @Test
+    func myTest() {
+        #expect(Bool(true))
+    }
+}