Git: Update git reset command from HEAD^ to HEAD~

[mathdebate09]

Because

The usage of caret selector (^) in the deeper look at git lesson might lead to confusion to make it continuous with rest of the lesson

This PR

• Update all references abut git reset HEAD^ to git reset HEAD~

Issue

Closes #28273

Additional Information

I believe the lesson file is path agnostic and I could find only one file about deeper look at git, though the issue author had linked it in ruby path, let me know if any revisions would be needed.

Pull Request Requirements

• [x] I have thoroughly read and understand The Odin Project curriculum contributing guide
• [x] The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• [x] The Because section summarizes the reason for this PR
• [x] The This PR section has a bullet point list describing the changes in this PR
• [x] If this PR addresses an open issue, it is linked in the Issue section
• [x] If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• [x] If any lesson files are included in this PR, they follow the Layout Style Guide