fix: collector port availability check in collector_test.sh

[anomit]

Fixes #152

Checklist

• My branch is up-to-date with upstream/develop branch.
• Everything works and tested for Python 3.8.0 and above.
• I ran pre-commit checks against my changes.
• I've written tests against my changes and all the current present tests are passing.

Current behaviour

The collector_test.sh script unconditionally searches for available ports and overwrites the LOCAL_COLLECTOR_PORT in the environment file whenever no active collector is found, regardless of whether the configured port is actually in use. This causes the script to ignore explicitly configured port values and replace them with the first available port in the range (50051-51050), even when the configured port is perfectly available.

New expected behaviour

The script now respects explicitly configured LOCAL_COLLECTOR_PORT values and only searches for alternative ports when there is an actual port conflict. When the configured port is available, it uses that port without modifying the environment file. Port replacement only occurs when the configured port is genuinely in use by another service.

Change logs

Fixed

• Fixed unconditional port override behavior that ignored explicitly configured LOCAL_COLLECTOR_PORT values
• Eliminated duplicate port connectivity checks by reusing test_ping results from initial connectivity test
• Fixed environment file being unnecessarily modified when configured port is available

Deployment Instructions

• Pull the dockerify branch of the lite node and confirm whether the free local collector port as configured in your env is correctly picked up by the build.sh setup and local collector spawned on it.

[xadahiya]

LGTM!

[xadahiya]

LGTM!

[SwaroopH]

LGTM