Update zksync-env.sh

[Alexlesch98]

Changes made:

1.Improved formatting and indentation for better readability.

2. Enclosed variable expansions in double quotes to prevent word splitting and globbing issues.
3. Replaced some subshell executions ($(...)) with command substitution (cmd || true) for better error handling.
4. Reorganized the script structure for clarity and easier maintenance.
5. Added missing double quotes around file paths to handle paths with spaces or special characters properly.
6. Simplified some conditional statements and error handling.
7. Improved comments for clarity.

[NDT3117]

Nice