fix: replace removed std.Build.host with std.Build.graph.host

assets/zig-code/build-system/1-simple-executable/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const exe = b.addExecutable(.{
         .name = "hello",
         .root_source_file = b.path("hello.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     b.installArtifact(exe);

assets/zig-code/build-system/11-zig-tool/build.zig

@@ -5,7 +5,7 @@ pub fn build(b: *std.Build) void {
     const tool = b.addExecutable(.{
         .name = "word_select",
         .root_source_file = b.path("tools/word_select.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     const tool_step = b.addRunArtifact(tool);

assets/zig-code/build-system/12-embedfile/build.zig

@@ -5,7 +5,7 @@ pub fn build(b: *std.Build) void {
     const tool = b.addExecutable(.{
         .name = "word_select",
         .root_source_file = b.path("tools/word_select.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     const tool_step = b.addRunArtifact(tool);

assets/zig-code/build-system/13-import/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const tool = b.addExecutable(.{
         .name = "generate_struct",
         .root_source_file = b.path("tools/generate_struct.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     const tool_step = b.addRunArtifact(tool);

assets/zig-code/build-system/conditional-compilation/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const exe = b.addExecutable(.{
         .name = "app",
         .root_source_file = b.path("app.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     const version = b.option([]const u8, "version", "application version string") orelse "0.0.0";

assets/zig-code/build-system/convenience-run-step/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const exe = b.addExecutable(.{
         .name = "hello",
         .root_source_file = b.path("hello.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     b.installArtifact(exe);

assets/zig-code/build-system/system-libraries/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const exe = b.addExecutable(.{
         .name = "zip",
         .root_source_file = b.path("zip.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     exe.linkSystemLibrary("z");

assets/zig-code/build-system/write-files/build.zig

@@ -4,7 +4,7 @@ pub fn build(b: *std.Build) void {
     const exe = b.addExecutable(.{
         .name = "app",
         .root_source_file = b.path("src/main.zig"),
-        .target = b.host,
+        .target = b.graph.host,
     });
 
     const version = b.option([]const u8, "version", "application version string") orelse "0.0.0";

build.zig

@@ -189,7 +189,7 @@ fn runZigScripts(
     paths: []const []const u8,
 ) void {
     const doctest_dep = b.dependency("doctest", .{
-        .target = b.host,
+        .target = b.graph.host,
         .optimize = .Debug,
     });
     const doctest_exe = doctest_dep.artifact("doctest");
@@ -228,7 +228,7 @@ fn runSingleZigScript(
 
 pub fn oldBuild(b: *std.Build) void {
     const doctest_dep = b.dependency("doctest", .{
-        .target = b.host,
+        .target = b.graph.host,
         .optimize = .Debug,
     });
     const doctest_exe = doctest_dep.artifact("doctest");