ssm get-parameter can't get secret

### Describe the bug

I can't get secret through ssm with a specific name, both on Win and Linux. It looks like some internals are adding `null` suffix.

### Regression Issue

- [ ] Select this option if this issue appears to be a regression.

### Expected Behavior

Be able to get secret with a name `shared-secret-alpha` through ssm

### Current Behavior

I'm getting error:
```
aws: [ERROR]: An error occurred (ParameterNotFound) when calling the GetParameter operation: An error occurred (ParameterNotFound) when referencing Secrets Manager: Secret aws/reference/secretsmanager/shared-secret-alphanull not found.
```
with added `null` at the end of secret name

### Reproduction Steps

`aws ssm get-parameter --name "/aws/reference/secretsmanager/alpha" --with-decryption`

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### CLI version used

aws-cli/2.36.7 Python/3.14.6 Windows/11 exe/AMD64

### Environment details (OS name and version, etc.)

aws-cli/2.36.13 Python/3.14.6 Linux/6.18.33.2-microsoft-standard-WSL2 script-exe/x86_64.ubuntu.24