Update code samples and prose for ponyc 0.70.0 constraint cap change

code-samples/appendices-examples-test-helper.pony

@@ -9,7 +9,7 @@ fun tag assert_error(test: ITest, msg: String = "") ?
 fun tag expect_error(test: ITest box, msg: String = ""): Bool
 fun tag assert_is (expect: Any, actual: Any, msg: String = "") ?
 fun tag expect_is (expect: Any, actual: Any, msg: String = ""): Bool
-fun tag assert_eq[A: (Equatable[A] #read & Stringable)]
+fun tag assert_eq[A: (Equatable[A] #read & Stringable #read)]
   (expect: A, actual: A, msg: String = "") ?
-fun tag expect_eq[A: (Equatable[A] #read & Stringable)]
+fun tag expect_eq[A: (Equatable[A] #read & Stringable #read)]
   (expect: A, actual: A, msg: String = ""): Bool

code-samples/control-structures-iftype-capability.pony

@@ -14,7 +14,7 @@ actor Main
     let cat2: Cat val = Cat
     maybe_rename[Cat val](cat2, env)
 
-  fun maybe_rename[A: Animal](a: A, env: Env) =>
+  fun maybe_rename[A: Animal #any](a: A, env: Env) =>
     iftype A <: Cat ref then
       a.set_name("Kitty")
       env.out.print(a.name())

code-samples/generics-and-reference-capabilities-explicit-constraint-and-default-capability.pony

@@ -1 +1 @@
-class Foo[A: Any]
+class Foo[A: Any #any]

docs/generics/generics-and-reference-capabilities.md

@@ -6,7 +6,7 @@ In the examples presented previously we've explicitly set the reference capabili
 --8<-- "generics-foo-with-any-val.pony::1"
 ```
 
-If the capability is left out of the type parameter then the generic class or function can accept any reference capability. This would look like:
+To accept any reference capability, use `#any` as the capability on the constraint. This would look like:
 
 ```pony
 --8<-- "generics-and-reference-capabilities-explicit-constraint-and-default-capability.pony"