glob operators do not always work

[anilbey]

Describe the bug
Hi I think there is an issue with the glob.

Here is the directory
❯ tree examples/1-singlecell -L 1
examples/1-singlecell
├── hoc
├── morphology
├── singlecell.ipynb
└── x86_64

pytest --nbmake examples//1-singlecell/singlecell.ipynb works
pytest --nbmake examples/**/*ipynb does not work
pytest --nbmake **/*ipynb does not work

When they don't work the error is the following:

It says ERROR: file or directory not found: **/*ipynb

To Reproduce

1. Use this versions

• nbmake==1.4.1
• pytest==7.3.2

2. Create a directory like the one I created and repeat the 3 commands provided above.

Expected behavior

The wildcard character to detect the .ipynb files in the inner directories.