feat(dev): use nanobind as python package instead of git submodule

Note that the `execute_process` call technically isn't necessary
when running in skbuild, since it already sets up CMake search paths accordingly,
but it probably still doesn't hurt to have.

Author: shiftinv

.gitmodules

@@ -1,6 +1,3 @@
 [submodule "libdave"]
 	path = libdave
 	url = https://github.com/shiftinv/libdave.git
-[submodule "nanobind"]
-	path = nanobind
-	url = https://github.com/wjakob/nanobind

CMakeLists.txt

@@ -49,7 +49,12 @@ find_package(
     REQUIRED COMPONENTS Interpreter Development.Module
     OPTIONAL_COMPONENTS Development.SABIModule
 )
-add_subdirectory(nanobind)
+
+# Find (and load) nanobind, see https://nanobind.readthedocs.io/en/latest/building.html#finding-nanobind
+execute_process(
+  COMMAND "${Python_EXECUTABLE}" -m nanobind --cmake_dir
+  OUTPUT_STRIP_TRAILING_WHITESPACE OUTPUT_VARIABLE nanobind_ROOT)
+find_package(nanobind CONFIG REQUIRED)
 
 nanobind_add_module(_dave_impl STABLE_ABI src/dave.cpp)
 

pyproject.toml

@@ -18,8 +18,7 @@ dev = [
 ]
 # note: these should match `build-system.requires`
 build = [
-  # FIXME: actually use nanobind python package instead of git submodule
-  "nanobind>=2.9.2",
+  "nanobind~=2.9.2",
   "scikit-build-core>=0.11.0"
 ]
 nox = [
@@ -35,7 +34,7 @@ typing = [
 ]
 
 [build-system]
-requires = ["nanobind>=2.9.2", "scikit-build-core>=0.11.0"]
+requires = ["nanobind~=2.9.2", "scikit-build-core>=0.11.0"]
 build-backend = "scikit_build_core.build"
 
 [tool.poe.tasks]
@@ -54,7 +53,6 @@ include = [
 line-length = 100
 extend-exclude = [
   "libdave/",
-  "nanobind/",
 ]
 
 [tool.ruff.lint]