justfile: allow passing args to meson compile

My main motivation for this change is to limit the amount of compile
jobs to make sure my machine is still usable for something else when
building a fresh Lix locally.

Also made `build` a dependency of `install`: this is analogous to
`make install` in CppNix where this both recompiles changed files and
installs the artifacts into `outputs/out`. May be a little more pleasant
to work with that, especially when you're used to contributing to
CppNix.

Change-Id: I321e2b0daf1c5e20f82c04e2dd158056c80ed86c

justfile

@@ -6,13 +6,13 @@ clean:
 setup:
     meson setup build --prefix="$PWD/outputs/out"
 
-build:
+build *OPTIONS:
-    meson compile -C build
+    meson compile -C build {{ OPTIONS }}
 
 compile:
     just build
 
-install:
+install *OPTIONS: (build OPTIONS)
     meson install -C build
 
 test *OPTIONS: