fix issue with --limit not working correctly

[shahzebsiddiqui]

@vsoch the original codebase doesnt honor the --limit correctly as shown below.

With --limit 1 i should see 1 entry

(singularity-hpc) ➜  singularity-hpc git:(main) ✗ shpc show --filter tensorflow --limit 1
/Users/shahzebsiddiqui/.local/share/virtualenvs/singularity-hpc-ckWqEIW1/lib/python3.9/site-packages/urllib3/__init__.py:35: NotOpenSSLWarning: urllib3 v2 only supports OpenSSL 1.1.1+, currently the 'ssl' module is compiled with 'LibreSSL 2.8.3'. See: https://github.com/urllib3/urllib3/issues/3020
  warnings.warn(
SINGULARITY is not installed, functionality might be limited.
jupyter/tensorflow-notebook
nvcr.io/nvidia/tensorflow

Also with --limit 0 i end up seeing more entries so this doesnt work either

(singularity-hpc) ➜  singularity-hpc git:(main) ✗ shpc show --filter tensorflow --limit 0
/Users/shahzebsiddiqui/.local/share/virtualenvs/singularity-hpc-ckWqEIW1/lib/python3.9/site-packages/urllib3/__init__.py:35: NotOpenSSLWarning: urllib3 v2 only supports OpenSSL 1.1.1+, currently the 'ssl' module is compiled with 'LibreSSL 2.8.3'. See: https://github.com/urllib3/urllib3/issues/3020
  warnings.warn(
SINGULARITY is not installed, functionality might be limited.
jupyter/tensorflow-notebook
nvcr.io/nvidia/tensorflow
quay.io/jupyter/tensorflow-notebook
quay.io/pawsey/tensorflow
rocm/tensorflow
tensorflow/tensorflow

With the proposed change i was able to fix this as shown below

(singularity-hpc) ➜  singularity-hpc git:(fix_limit_output) ✗ shpc show --filter tensorflow --limit 1
/Users/shahzebsiddiqui/.local/share/virtualenvs/singularity-hpc-ckWqEIW1/lib/python3.9/site-packages/urllib3/__init__.py:35: NotOpenSSLWarning: urllib3 v2 only supports OpenSSL 1.1.1+, currently the 'ssl' module is compiled with 'LibreSSL 2.8.3'. See: https://github.com/urllib3/urllib3/issues/3020
  warnings.warn(
SINGULARITY is not installed, functionality might be limited.
jupyter/tensorflow-notebook

(singularity-hpc) ➜  singularity-hpc git:(fix_limit_output) ✗ shpc show --filter tensorflow --limit 0
/Users/shahzebsiddiqui/.local/share/virtualenvs/singularity-hpc-ckWqEIW1/lib/python3.9/site-packages/urllib3/__init__.py:35: NotOpenSSLWarning: urllib3 v2 only supports OpenSSL 1.1.1+, currently the 'ssl' module is compiled with 'LibreSSL 2.8.3'. See: https://github.com/urllib3/urllib3/issues/3020
  warnings.warn(
SINGULARITY is not installed, functionality might be limited.
(singularity-hpc) ➜  singularity-hpc git:(fix_limit_output) ✗ 

[vsoch]

Setting limit to 0 is normally akin to unset (no limit). Asking for a limit of 0 and getting no results is not something that user would logically do. My preference is either to keep limit of 0 to mean no limit, or if the user defines is to be <1, to print a quick error message that the limit must be greater than or equal to 1 and then exit cleanly.