Fix config.h bool parsing

[zvecr]

Description

PR #26163 has #define NKRO_DEFAULT_ON true within a config.h.

Running qmk info -f json -kb owlab/link65/hotswap incorrectly produces:

    "host": {
        "default": {
            "nkro": false
        }
    },

qmk_firmware/lib/python/qmk/info.py

Line 660 in ccc6c6c

return config_value in true_values

At the point the conversion is handled, the config_value is a string of value "true". This is not within the currently expected true values so returns false.

Also updated variable name as it is a constant.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).