TYP: numba stub
partial stub to preserve type signatures for decorated functions.

draft since will rebase once #43828 is merged.

cc @twoertwein @mroeschke 
There are a few more cases of `numba.jit` that have ignored comments. 

pandas/core/window/online.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]
pandas/core/window/numba_.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]
pandas/core/window/numba_.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]
pandas/core/window/numba_.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]
pandas/core/window/numba_.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]
pandas/core/_numba/executor.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]
pandas/core/groupby/numba_.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]
pandas/core/groupby/numba_.py:    @numba.jit(nopython=nopython, nogil=nogil, parallel=parallel)  # type: ignore[misc]

edit: because of `import_optional_dependency` @twoertwein merge when ready here. can certainly be followups to fix more stuff.