Fix GitSync Probe Validation and Refactor Redis Probe Definitions

[Shubham-astro]

Problem

The deployment validation was failing with the following error:

dags.gitSync.livenessProbe: Additional property successThreshold is not allowed
dags.gitSync.readinessProbe: Additional property successThreshold is not allowed

This occurred because the schema was using the generic io.k8s.api.core.v1.Probe definition which includes successThreshold for all probe types. However, according to Kubernetes specifications:

Liveness probes: successThreshold is not allowed (always implicitly 1)
Readiness probes: successThreshold is allowed

Additionally, Redis probe configurations were hardcoded with specific properties instead of using reusable probe definitions.

Issue

https://github.com/astronomer/issues/issues/7291

Changes

1. Created Specific Probe Definitions
   Added two new probe definitions in the schema's definitions section:

LivenessProbe: Excludes successThreshold property (Kubernetes compliant)
ReadinessProbe: Includes successThreshold property (allows configuration)

2. Refactored Redis Probe Definitions
   Replaced hardcoded Redis probe properties with reusable probe references