Updating unworking zsh script for adding flutter into the PATH

[SuwonJ]

Description of what this PR is changing or adding, and why:
Changing the unworking zsh script for adding flutter into the PATH. The only difference is changing "~/development/flutter/bin:$PATH" into "$HOME/development/flutter/bin:$PATH"

Issues fixed by this PR (if any):
#11139

PRs or commits this PR depends on (if any):

Presubmit checklist

• This PR is marked as draft with an explanation if not meant to land until a future stable release.
• This PR doesn’t contain automatically generated corrections (Grammarly or similar).
• This PR follows the Google Developer Documentation Style Guidelines — for example, it doesn’t use i.e. or e.g., and it avoids I and we (first person).
• This PR uses semantic line breaks of 80 characters or fewer.

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[TahaTesser]

LGTM