fix(shell-sync): remove interactive shell mode and reduce security false positives

[VitalyMarom]

Summary

This PR removes the explicit -i (interactive) argument when spawning Fish-like shells during shell environment detection.

Related Issues:

#2377
#2376

Motivation

The interactive flag is not required for environment computation when the shell is already started as a login shell (-l).
Using an interactive shell for environment discovery may also trigger security monitoring and endpoint protection tools. Some EDR and security products can flag this behavior as suspicious shell-spawning activity or reverse shell-like behavior, resulting in false-positive security alerts.
Additionally, shell environment variables intended for GUI applications should generally be configured in login shell initialization files. For example, in Zsh the recommended location is: ~/.zprofile

Since .zprofile is evaluated by login shells, running an additional interactive shell should not be necessary for environment synchronization.

Changes

• Removed the Fish-specific -i argument.
• Removed the associated command modification used for interactive shell execution.
• Updated unit tests to expect: ["-l"] instead of ["-l", "-i"]

Benefits

• Reduces the likelihood of triggering security-tool false positives.
• Avoids unnecessary interactive shell execution.
• Aligns environment detection with standard login-shell behavior.
• Encourages use of login-shell configuration files such as .zprofile for environment variables.
• Simplifies shell-specific logic.

Testing

Updated the existing test to verify that Fish-like shells are spawned with: ["-l"] and confirmed that environment detection continues to work as expected.