optimize scanning of vulkan shader files in ncnn_add_layer()
#7364
test-coverage.yml
on: pull_request
linux-gcc-gpu-t4
50m 17s
linux-gcc-x64-sde-combined
1h 7m
linux-gcc-gpu-llvmpipe
17m 41s
Matrix: linux-gcc-riscv64-rvv
Matrix: linux-gcc-x64-sde