feat(eks): add support for EC2, HYBRID_LINUX, and HYPERPOD_LINUX access entry types (#36350)

### Issue # (if applicable)

Closes #34394.

### Reason for this change

When provisioning an EKS cluster in Auto Mode with custom node roles, users need to grant the node role access to the cluster with the `EC2` access entry type. Currently, the `grantAccess()` method doesn't support specifying the access entry type, defaulting to `STANDARD`, which prevents nodes from joining Auto Mode clusters.

Additionally, the `AccessEntryType` enum is missing three CloudFormation-supported types: `EC2`, `HYBRID_LINUX`, and `HYPERPOD_LINUX`.

### Description of changes

This PR adds support for specifying access entry types in the `grantAccess()` method and extends the `AccessEntryType` enum with missing CloudFormation-supported values.

**Changes made**:
- Extended `AccessEntryType` enum with three new values:
  - `EC2` - For EKS Auto Mode node roles
  - `HYBRID_LINUX` - For EKS Hybrid Nodes
  - `HYPERPOD_LINUX` - For Amazon SageMaker HyperPod
- Added optional `accessEntryType` parameter to `Cluster.grantAccess()` method
- Updated private `addToAccessEntry()` method to pass type through to AccessEntry constructor
- Applied changes to both `@aws-cdk/aws-eks-v2-alpha` (alpha) and `aws-cdk-lib/aws-eks` (stable) packages

**API changes**:
```typescript
// Before (still works - backward compatible)
cluster.grantAccess('MyAccess', roleArn, [policy]);

// After (new capability)
cluster.grantAccess('MyAccess', roleArn, [policy], AccessEntryType.EC2);
```

**CloudFormation impact**:
- When `accessEntryType` is provided: `Type` property is set in `AWS::EKS::AccessEntry`
- When `accessEntryType` is not provided: `Type` property remains undefined (backward compatible)

**No breaking changes**: This is a fully backward-compatible feature addition. The new parameter is optional and placed at the end of the method signature. All existing code continues to work without modification.

### Describe any new or updated permissions being added

N/A - No new IAM permissions required. This change only exposes existing CloudFormation access entry types through the CDK L2 API.

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: pahud