disable git clone warnings upon make setup

[ahbarnett]

Users could think this warning is an error:

(base) alex@ross /home/alex/numerics/finufft> make setup
mkdir -p deps
Checking XSIMD external dependency...
Cloning repository https://github.com/xtensor-stack/xsimd.git at tag 13.0.0 into directory deps/xsimd
Cloning into 'deps/xsimd'...
remote: Enumerating objects: 253, done.
remote: Counting objects: 100% (253/253), done.
remote: Compressing objects: 100% (209/209), done.
remote: Total 253 (delta 106), reused 97 (delta 40), pack-reused 0 (from 0)
Receiving objects: 100% (253/253), 297.80 KiB | 11.45 MiB/s, done.
Resolving deltas: 100% (106/106), done.
Note: switching to '5ac7edf30d0f519e0b7344b933382e4fc02fdee7'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by switching back to a branch.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -c with the switch command. Example:

  git switch -c <new-branch-name>

Or undo this operation with:

  git switch -

Turn off this advice by setting config variable advice.detachedHead to false

xsimd installed in deps/xsimd
mkdir -p deps
Checking DUCC external dependency...
Cloning repository https://gitlab.mpcdf.mpg.de/mtr/ducc.git at tag ducc0_0_35_0 into directory deps/ducc
Cloning into 'deps/ducc'...
remote: Enumerating objects: 186, done.
remote: Counting objects: 100% (186/186), done.
remote: Compressing objects: 100% (176/176), done.
remote: Total 186 (delta 9), reused 72 (delta 2), pack-reused 0 (from 0)
Receiving objects: 100% (186/186), 485.32 KiB | 817.00 KiB/s, done.
Resolving deltas: 100% (9/9), done.
Note: switching to 'b3de68c22c09446d4f04d62a64c7f2d7ddfa8f68'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by switching back to a branch.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -c with the switch command. Example:

  git switch -c <new-branch-name>

Or undo this operation with:

  git switch -

Turn off this advice by setting config variable advice.detachedHead to false

touch deps/ducc/.finufft_has_ducc
DUCC installed in deps/ducc

Could we change config in the make task:?

Turn off this advice by setting config variable advice.detachedHead to false