Add required helm repositories for Jaeger demo deployment (#7403)

## Which problem is this PR solving?
- Part of #7115 
- Added necessary helm repositories for first time runs 

## Checklist
- [ ] I have read
https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
- [ ] I have signed all commits
- [ ] I have added unit tests for the new functionality
- [ ] I have run lint and test steps successfully
  - for `jaeger`: `make lint test`
  - for `jaeger-ui`: `npm run lint` and `npm run test`

Signed-off-by: chahat sagar <[email protected]>

Author: chahatsagarmain

examples/oci/deploy-all.sh

@@ -11,6 +11,11 @@ if [ ! -d "helm-charts" ]; then
   git clone https://github.com/jaegertracing/helm-charts.git
   cd helm-charts
   git checkout v2
+  echo "Adding required Helm repositories..."
+  helm repo add bitnami https://charts.bitnami.com/bitnami
+  helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
+  helm repo add incubator https://charts.helm.sh/incubator
+  helm repo update
   helm dependency build ./charts/jaeger
   cd ..
 else