docs: fix typos in README files (#37396)

### Issue

N/A (self-discovered typos)

### Reason for this change

Several README files contain spelling errors.

### Description of changes

- `aws-eks-v2/README.md`: "serivceToken" → "serviceToken"
- `aws-events/README.md`: "wether" → "whether"
- `aws-route53-targets/README.md`: "avaiable" → "available"
- `cx-api/README.md`: "unsecure connnections" → "insecure connections"

### Description of how you validated changes

Documentation-only changes. No functional impact.

### 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)

Author: syukawa-gh

packages/aws-cdk-lib/aws-eks-v2/README.md

@@ -557,7 +557,7 @@ If you want to use an existing kubectl provider function, for example with tight
 
 ```ts
 const handlerRole = iam.Role.fromRoleArn(this, 'HandlerRole', 'arn:aws:iam::123456789012:role/lambda-role');
-// get the serivceToken from the custom resource provider
+// get the serviceToken from the custom resource provider
 const functionArn = lambda.Function.fromFunctionName(this, 'ProviderOnEventFunc', 'ProviderframeworkonEvent-XXX').functionArn;
 const kubectlProvider = eks.KubectlProvider.fromKubectlProviderAttributes(this, 'KubectlProvider', {
   serviceToken: functionArn,

packages/aws-cdk-lib/aws-events/README.md

@@ -366,7 +366,7 @@ For more information, see [KMS key options for event bus encryption](https://doc
 
 ## Configuring logging
 
-To configure logging for an Event Bus, leverage the LogConfig property. It allows different level of logging (NONE, INFO, TRACE, ERROR) and wether to include details or not.
+To configure logging for an Event Bus, leverage the LogConfig property. It allows different level of logging (NONE, INFO, TRACE, ERROR) and whether to include details or not.
 
 ```ts
 import { EventBus, IncludeDetail, Level } from 'aws-cdk-lib/aws-events';

packages/aws-cdk-lib/aws-route53-targets/README.md

@@ -222,7 +222,7 @@ new route53.ARecord(this, 'AliasRecord', {
 });
 ```
 
-If Elastic Beanstalk environment URL is not avaiable at synth time, you can specify Hosted Zone ID of the target
+If Elastic Beanstalk environment URL is not available at synth time, you can specify Hosted Zone ID of the target
 
 ```ts
 import { RegionInfo } from 'aws-cdk-lib/region-info';

packages/aws-cdk-lib/cx-api/README.md

@@ -555,7 +555,7 @@ When this feature flag is enabled, the default behaviour of OIDC Provider's cust
 default to reject unauthorized connections when downloading CA Certificates.
 
 When this feature flag is disabled, the behaviour will be the same as current and will allow downloading
-thumbprints from unsecure connnections.
+thumbprints from insecure connections.
 
 _cdk.json_