Feature: Add guide to install system dependencies with pixi

先從 devguide 中現有的系統層級相依性安裝指南開始，並將其與提議的 pixi.toml 工作流程進行比較。新增一個簡潔的基於 pixi 的選項或連結，涵蓋 issue 中所示的相依性與環境設定，然後確認開發環境設定說明完整且易於理解。

Describe the enhancement or feature you would like

I've stopped using brew on my macOS and I'm instead using pixi whenever I need system-level dependencies. This works very well in practice even for building CPython and I can do things like pixi run configure and it automatically sets up all of the system dependencies and runs configure. Doing that requires setting some environment variables here and there, but I've done that in a pixi.toml and it's all automated. It looks somewhat like this:

[project]
name = "cpython-dev"
channels = ["conda-forge"]
platforms = ["osx-arm64"]

[dependencies]
gdbm = "*"
libmpdec-devel = "*"
openssl = "3.*"
pkg-config = "*"
tk = "*"
xz = "*"
zstd = "*"
zlib = "*"

[tasks.configure]
cmd = "./configure --with-openssl=$CONDA_PREFIX"

[tasks.configure.env]
PKG_CONFIG_PATH = "$CONDA_PREFIX/lib/pkgconfig"
GDBM_CFLAGS = "-I$CONDA_PREFIX/include"
GDBM_LIBS = "-L$CONDA_PREFIX/lib -lgdbm"
TCLTK_CFLAGS = "$(pkg-config --cflags tcl tk)"
# tcl.pc and tk.pc files contain stub libraries, but those do not extist
# in the conda package
TCLTK_LIBS = "$(pkg-config --libs tcl tk | sed 's/-l[^ ]*stub[^ ]*//g')"
LDFLAGS = "-Wl,-rpath,$CONDA_PREFIX/lib"

It's a bit too much to propose adding this to the CPython repo, at least for now. However, pointing to this as a way to install system-level dependencies in the devguide doesn't sounds like a bad idea to me.

Thoughts? Is there an appetite for this? If so, I can start drafting a PR.

Describe alternatives you have considered

No response

Additional context

No response