build: add option to install tests

build.zig

@@ -82,5 +82,7 @@ pub fn build(b: *std.Build) void {
     const test_step = b.step("test", "Run tests");
     test_step.dependOn(&run_tests.step);
 
+    if (b.option(bool, "install_tests", "Install the tests executable to the output directory") orelse false) {
         b.installArtifact(tests);
     }
+}