Deps: Drop the experimental support for n2 builds

n2 is missing some features and doesn't seem as actively maintained as ninja itself. Sadly, the speedup from "better incremental builds" isn't very noticeable in practice. On the other hand, using n2 instead of ninja in the CI workflow adds a full minute for building Rust code with `cargo`.

I'm not too happy about the Rust toolchain dependency in general (although it's also required for wgpu-native currently), so that's another reason to stick with ninja for the time being. It can still be used with an alias if needed, but I don't know that it's worth supporting two mostly identical build tools when I'd actually prefer to have zero.

.github/workflows/ci-linux.yml

@@ -39,9 +39,6 @@ jobs:
       - name: Install Ninja
         run: sudo apt-get install ninja-build
 
-      - name: Install n2
-        run: cargo install --git https://github.com/evmar/n2
-
       # Can't actually be used on CI runners, but we need the headers for embedding webview
       - name: Install WebKitGTK
         run: sudo apt-get install gtk+-3.0-dev webkit2gtk-4.1-dev --yes

unixbuild.sh

@@ -15,15 +15,7 @@ $LUAJIT_EXE ninjabuild.lua
 # LuaJIT's jit module is implemented in Lua and needs to be loaded via LUA_PATH for bytecode generation
 export LUA_PATH="$BUILD_DIR/?.lua;./?.lua"
 
-if which n2 > /dev/null; then # Using n2 speeds up local development as it has better change detection
-    BUILD_TOOL=n2
-else # Ninja works just as well and is expected to be installed in all cases (required for building deps via CMake)
-    BUILD_TOOL=ninja
-fi
-
-echo "Selected build tool: $BUILD_TOOL"
-
 # This will only work after the dependencies have been built! (Run the deps/build-X.sh scripts manually at least once)
 # The reason this is excluded from the ninja build is to eliminate propagated errors that are difficult to debug/misleading
 # It's much easier to see if the dependencies could be built independently and they don't usually need rebuilding anyway
-$BUILD_TOOL
+ninja