Tests fail on arm64

[bowlofeggs]

lnav version
v0.11.1

Describe the bug
A gentoo contributor filed a ticket describing a test failure on the arm64 architecture. You can download the full logs from the Gentoo ticket if you wish, but here's a sample from the output:

✘ error: invalid JSON
 --> {test_dir}/bad-config-json/formats/invalid-json/format.json:4
 | parse error: object key and value must be separated by a colon (':') 
 |           ar_log": {         "abc"     } }                          
 |                      (right here) ------^                           
 |                                                                     
⚠ warning: format file is missing “$schema” property
 --> {test_dir}/bad-config-json/formats/invalid-json/format.json
 =   note: the schema specifies the supported format version and can be used with editors to automatically validate the file
 =   help: add the following property to the top-level JSON object:
             "$schema": "https://lnav.org/schemas/format-v1.schema.json",
✘ error: “abc(” is not a valid regular expression
 reason: missing closing parenthesis
 --> /invalid_key_log/level-pointer
 | abc(                                    
 |     ^ missing closing parenthesis       
 --> {test_dir}/bad-config-json/formats/invalid-key/format.json:4
 |         "level-pointer": "abc(",        
 = help: Property Synopsis
           /invalid_key_log/level-pointer 
         Description
           A regular-expression that matches the JSON-pointer of the level property

To Reproduce
Run the tests on an arm64 system.

[tstack]

One possible reason is that the NO_COLOR environment variable is set... do you happen to know if that's the case? Looking at the env dump in the build logs, it seems like that might be the case.

I've pushed a change to unset NO_COLOR in the the test environment.