Reverted commits that deprecated the build.zig files, and added a note to all of them stating version of zig they were using (#3060)

* Revert "Fixed broken build.zig files. Now works with latest stable compiler (as of commit, latest is 0.10.1) (#3045)"

This reverts commit de748dfffe so that zig
build script works with master branch of zig.

* Added a note to build.zig files that denotes what version of zig they have been tested with.

* Standardised the note in the build.zig files

build.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const raylib = @import("src/build.zig");
 
-pub fn build(b: *std.build.Builder) void {
+// This has been tested to work with zig master branch as of commit 87de821 or May 14 2023
+pub fn build(b: *std.Build) void {
     raylib.build(b);
 }

examples/build.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const builtin = @import("builtin");
 
+// This has been tested to work with zig master branch as of commit 87de821 or May 14 2023
 fn add_module(comptime module: []const u8, b: *std.Build, target: std.zig.CrossTarget, optimize: std.builtin.OptimizeMode) !*std.Build.Step {
     if (target.getOsTag() == .emscripten) {
         @panic("Emscripten building via Zig unsupported");

src/build.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 
-pub fn addRaylib(b: *std.build.Builder, target: std.zig.CrossTarget) *std.build.LibExeObjStep {
+// This has been tested to work with zig master branch as of commit 87de821 or May 14 2023
+pub fn addRaylib(b: *std.Build, target: std.zig.CrossTarget, optimize: std.builtin.OptimizeMode) *std.Build.CompileStep {
     const raylib_flags = &[_][]const u8{
         "-std=gnu99",
         "-D_GNU_SOURCE",
@@ -8,10 +9,10 @@ pub fn addRaylib(b: *std.build.Builder, target: std.zig.CrossTarget) *std.build.
         "-fno-sanitize=undefined", // https://github.com/raysan5/raylib/issues/1891
     };
 
-    const raylib = b.addStaticLibrary(std.Build.StaticLibraryOptions{
+    const raylib = b.addStaticLibrary(.{
         .name = "raylib",
         .target = target,
-        .optimize = b.standardOptimizeOption(.{ .preferred_optimize_mode = .ReleaseSafe }),
+        .optimize = optimize,
     });
     raylib.linkLibC();
 
@@ -103,7 +104,7 @@ pub fn addRaylib(b: *std.build.Builder, target: std.zig.CrossTarget) *std.build.
     return raylib;
 }
 
-pub fn build(b: *std.build.Builder) void {
+pub fn build(b: *std.Build) void {
     // Standard target options allows the person running `zig build` to choose
     // what target to build for. Here we do not override the defaults, which
     // means any target is allowed, and the default is native. Other options
@@ -112,10 +113,10 @@ pub fn build(b: *std.build.Builder) void {
     // Standard optimization options allow the person running `zig build` to select
     // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
     // set a preferred release mode, allowing the user to decide how to optimize.
-    // const optimize = b.standardReleaseOptions();
+    const optimize = b.standardOptimizeOption(.{});
 
-    const lib = addRaylib(b, target);
+    const lib = addRaylib(b, target, optimize);
-    b.installFile("src/raylib.h", "raylib.h");
+    lib.installHeader("src/raylib.h", "raylib.h");
     b.installArtifact(lib);
 }