Copyright detection regression after implementing gibberish detection

Certain copyrights are not detected anymore as the gibberish detector identifies it as gibberish:

https://github.com/aboutcode-org/scancode-toolkit/blob/2402-detect-gibberish-copyright/tests/cluecode/data/copyrights/scilab-Scilab#L67
- an instance of `Scilab (c) INRIA-ENPC.` was not detected
- `c) INRIA-ENPC.` is identified as gibberish

https://github.com/aboutcode-org/scancode-toolkit/blob/2402-detect-gibberish-copyright/tests/cluecode/data/copyrights/misco4/linux-copyrights/Documentation/networking/arcnet-hardware.txt#L32
- this did not detect `Copyright Waterloo Microsystems Inc. 1985`
- `@Copyright` is identified as gibberish

https://github.com/aboutcode-org/scancode-toolkit/blob/2402-detect-gibberish-copyright/tests/cluecode/data/authors/trailing_date#L3C19-L3C59
- `Alexander Kanavin ` was not detected
- `* : commit 3debe362faa62e5b381b880e3ba23aee07c85f6e Author:` is detected as gibberish

_Originally posted by @JonoYang in https://github.com/aboutcode-org/scancode-toolkit/issues/4610#issuecomment-3560081396_