ggshield fails with long paths

[agateau-gg]

Environment

• ggshield version: 1.13.5
• Operating system (Linux, macOS, Windows): any
• Operating system version: any
• Python version: 3.8.10

Describe the bug

When scanning a file whose path is longer than 255, ggshield fails.

Steps to reproduce:

1. Create a long file. Can be done with:

   mkdir tmp  # use a dir because Python does not want to create a file longer than 255 chars
   python -c 'open("tmp/" + "l" * 255, "w").write("foo")'
   

2. Run command ggshield secret scan path tmp/l*

Actual result:

Scanning Path... ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 100% 1 files scanned out of 1 0:00:00
Error: Error scanning, network error occurred: {0: {'filename': ['Longer than maximum length 256.']}}

Expected result: Scan should succeed