fix: add timezone indicator to backend date strings

[TudorGR]

Description

Fixes #1343

The backend returns dates in YYYY-MM-DDThh:mm:ss format without timezone information. This PR adds the 'Z' suffix to these date strings to indicate they are in GMT/UTC, ensuring correct timezone handling.

Changes:

• Modified parseTime() function in src/api/gapsService.ts to append 'Z' to date strings that don't already have a timezone indicator
• The fix checks if the time string already has a timezone (ends with 'Z' or contains '+') before adding 'Z'
• Ensures backward compatibility with dates that already include timezone information

Technical details:

const timeString =
  typeof time === 'string' && !time.endsWith('Z') && !time.includes('+') ? `${time}Z` : time

This minimal change ensures all datetime strings from the backend are correctly interpreted as GMT/UTC before being converted to the Asia/Jerusalem timezone.

screenshots
N/A - This is a backend data parsing fix with no visible UI changes.

[github-actions]

Preview: https://s3.amazonaws.com/noam-gaash.co.il/19062570480/open-bus/1307/index.html
Preview Storybook: https://s3.amazonaws.com/noam-gaash.co.il/19062570480/open-bus/1307/storybook/index.html
Test Report (if available): 'https://s3.amazonaws.com/noam-gaash.co.il/19062570480/open-bus/3278beef1c0370c9782f26b026f945cf5b19e648/test-results/index.html'

[AvivAbachi]

@TudorGR @NoamGaash

1. the backend fix fix: rides_execution not retune time whit time zone open-bus-stride-api#52
2. because we are using @hasadna/open-bus-api-client is automacit convert it to Date

[NoamGaash]

@AvivAbachi Great! Sorry for opening this issue I didn't notice your fix 👏