False positive in numpy header

### Description

> Please leave a brief description of the bug or feature request:

See https://github.com/numpy/numpy/blob/main/numpy/_core/src/multiarray/nditer_pywrap.c#L7

```
{
"path": "test",
"type": "file",
"detected_license_expression": "(uoi-ncsa OR mit) AND unknown-license-reference",
"detected_license_expression_spdx": "(NCSA OR MIT) AND LicenseRef-scancode-unknown-license-reference",
"license_detections": [
{
"license_expression": "(uoi-ncsa OR mit) AND unknown-license-reference",
"license_expression_spdx": "(NCSA OR MIT) AND LicenseRef-scancode-unknown-license-reference",
"matches": [
{
"license_expression": "uoi-ncsa OR mit",
"license_expression_spdx": "NCSA OR MIT",
"from_file": "test",
"start_line": 5,
"end_line": 7,
"matcher": "3-seq",
"score": 9.43,
"matched_length": 5,
"match_coverage": 9.43,
"rule_relevance": 100,
"rule_identifier": "uoi-ncsa_or_mit_4.RULE",
"rule_url": "https://github.com/nexB/scancode-toolkit/tree/develop/src/licensedcode/data/rules/uoi-ncsa_or_mit_4.RULE",
"matched_text": " * The University of British Columbia\n *\n * See LICENSE.txt for the license.",
"matched_text_diagnostics": "The University of [British] [Columbia]\n *\n * [See] LICENSE.[txt] [for] [the] license."
},
{
"license_expression": "unknown-license-reference",
"license_expression_spdx": "LicenseRef-scancode-unknown-license-reference",
"from_file": "test",
"start_line": 7,
"end_line": 7,
"matcher": "3-seq",
"score": 83.33,
"matched_length": 5,
"match_coverage": 100.0,
"rule_relevance": 100,
"rule_identifier": "unknown-license-reference_404.RULE",
"rule_url": "https://github.com/nexB/scancode-toolkit/tree/develop/src/licensedcode/data/rules/unknown-license-reference_404.RULE",
"matched_text": " * See LICENSE.txt for the license.",
"matched_text_diagnostics": "See LICENSE.txt for [the] license."
}
],
"identifier": "uoi_ncsa_or_mit__and_unknown_license_reference-8accffbc-b41a-eb31-b7e4-09e7847ce0e8"
}
],
"license_clues": [],
"percentage_of_license_text": 7.34,
"scan_errors": []
}
```

### System configuration

> For bug reports, it really helps us to know:

* What OS are you running on? (Windows/MacOS/Linux)
* What version of scancode-toolkit was used to generate the scan file?
* What installation method was used to install/run scancode? (pip/source download/other)