[ntuple] use raw strings in ntuple_show for ease of reading

[silverweed]

Aesthetic-only change: use raw strings instead of string concatenation for the expected values in ntuple_show.

Checklist:

• tested changes locally
• updated the docs (if necessary)

[github-actions]

Test Results

    20 files      20 suites   3d 13h 0m 58s ⏱️
 3 275 tests  3 271 ✅ 0 💤 4 ❌
63 846 runs  63 842 ✅ 0 💤 4 ❌

For more details on these failures, see this check.

Results for commit c881e0e.

♻️ This comment has been updated with latest results.

[hahnjo]

I don't really mind either way, but I think there are again formatting-only changes in the commit that make it hard to determine which lines just have whitespace-changes and which are actually modified...

[silverweed]

there are again formatting-only changes in the commit that make it hard to determine which lines just have whitespace-changes and which are actually modified...

I think it's safe to say that nothing was modified in such a way that its meaning changed, otherwise the related test would have failed.

[pcanal]

LGETM