Steps to Reproduce

1. Run the code snippet
2. The fontFamilyFallback is different even though it should be the same.

Expected results:

In both TextStyle the fontFamilyFallback should be the same: ['packages/a/Roboto']

See also the test case of the PR: https://github.com/flutter/flutter/pull/118393/files#diff-c4bd56f1a544c160283efcdd6c1c98176a81779dd8a07ec752a6d088f83c3b8c

Actual results:

The first In both fontFamilyFallback looks like this: ['packages/a/Roboto']
while the second like this: ['packages/a/packages/a/Roboto']

const TextStyle style = TextStyle(fontFamilyFallback: <String>['Roboto'], package: 'a');
print(style.fontFamilyFallback); // ['packages/a/Roboto']

final copiedStyle = style.copyWith();
print(style.fontFamilyFallback); // ['packages/a/packages/a/Roboto'];

final copiedStyle = style.apply();
print(style.fontFamilyFallback); // ['packages/a/packages/a/Roboto'];

Ran on the latest main commit.