069_comptime4: replace comptime T: type => T: type and refactor a bit accordingly

- replaced instances of `comptime T: type` with `T: type` (080_anonymous_structs)
- left 065_builtins2.zig: 27:// 2. @typeInfo(comptime T: type) @import("std").builtin.Type

see [do not enforce function parameters to be marked comptime if only called at comptime](https://github.com/ziglang/zig/pull/18331)

exercises/069_comptime4.zig

@@ -1,11 +1,9 @@
 //
-// One of the more common uses of 'comptime' function parameters is
+// In Zig types are first class values
-// passing a type to a function:
 //
-//     fn foo(comptime MyType: type) void { ... }
+//     fn foo(MyType: type) void { ... }
 //
-// In fact, types are ONLY available at compile time, so the
+// Types are resolved at compile time.
-// 'comptime' keyword is required here.
 //
 // Please take a moment to put on the wizard hat which has been
 // provided for you. We're about to use this ability to implement
@@ -42,7 +40,7 @@ pub fn main() void {
 //     2) Sets the size of the array of type T (which is the
 //        sequence we're creating and returning).
 //
-fn makeSequence(comptime T: type, ??? size: usize) [???]T {
+fn makeSequence(T: type, ??? size: usize) [???]T {
     var sequence: [???]T = undefined;
     var i: usize = 0;
 

exercises/080_anonymous_structs.zig

@@ -31,7 +31,7 @@ const print = @import("std").debug.print;
 // This function creates a generic data structure by returning an
 // anonymous struct type (which will no longer be anonymous AFTER
 // it's returned from the function).
-fn Circle(comptime T: type) type {
+fn Circle(T: type) type {
     return struct {
         center_x: T,
         center_y: T,

patches/patches/069_comptime4.patch

@@ -4,9 +4,9 @@
  //     2) Sets the size of the array of type T (which is the
  //        sequence we're creating and returning).
  //
--fn makeSequence(comptime T: type, ??? size: usize) [???]T {
+-fn makeSequence(T: type, ??? size: usize) [???]T {
 -    var sequence: [???]T = undefined;
-+fn makeSequence(comptime T: type, comptime size: usize) [size]T {
++fn makeSequence(T: type, comptime size: usize) [size]T {
 +    var sequence: [size]T = undefined;
      var i: usize = 0;