build system caching ignores changes to new autodoc wasm source files

[xdBronch]

Zig Version

0.12.0-dev.3245+4f782d1e8

Steps to Reproduce and Observed Behavior

add autodoc generation like the following to a build.zig and run zig build

b.installDirectory(.{
    .source_dir = exe.getEmittedDocs(),
    .install_dir = .prefix,
    .install_subdir = "docs",
});

make a change to one of the files in zig/lib/docs/wasm and rerun zig build. the main.wasm wont be rebuilt and your changes ignored

Expected Behavior

the wasm file should be rebuilt with the new changes