array-key in template

[snapshotpl]

Bug report

Code snippet that reproduces the problem

After update to 0.12.79 from 0.12.78
https://phpstan.org/r/49cccaed-239c-4cfd-8701-7992f4663b53

Expected output

No error

[ondrejmirtes]

Fixed: phpstan/phpstan-src@d29d098