eks anywhere create packages doesn't accept files that is outside of the current directory

**What happened**: eks anywhere create packages failed since I specified a file path outside of the current directory

```
$pwd
~/Desktop/ClusterConfig/adot_deployment

$eksa create packages -f ../adot.yaml. # doesn't like relative path
--------------------------------------------------------------------------------------
The Amazon EKS Anywhere Curated Packages are only available to customers with the
Amazon EKS Anywhere Enterprise Subscription
--------------------------------------------------------------------------------------
Error: error: the path "../adot.yaml" does not exist

$eksa create packages -f ~/Desktop/ClusterConfig/adot.yaml # also doesn't like absolute path
--------------------------------------------------------------------------------------
The Amazon EKS Anywhere Curated Packages are only available to customers with the
Amazon EKS Anywhere Enterprise Subscription
--------------------------------------------------------------------------------------
Error: error: the path "/Users/ivyjin/Desktop/ClusterConfig/adot.yaml" does not exist

However, the below options work:
$ cd..
$ pwd
/Users/ivyjin/Desktop/ClusterConfig

$eksa create packages -f adot.yaml # relative path works
--------------------------------------------------------------------------------------
The Amazon EKS Anywhere Curated Packages are only available to customers with the
Amazon EKS Anywhere Enterprise Subscription
--------------------------------------------------------------------------------------
package.packages.eks.amazonaws.com/myadot created

eksa create packages -f ~/Desktop/ClusterConfig/adot.yaml # absolute path works
--------------------------------------------------------------------------------------
The Amazon EKS Anywhere Curated Packages are only available to customers with the
Amazon EKS Anywhere Enterprise Subscription
--------------------------------------------------------------------------------------
package.packages.eks.amazonaws.com/myadot created
```

**What you expected to happen**: eks anywhere create packages should succeed

**How to reproduce it (as minimally and precisely as possible)**:
See above

**Anything else we need to know?**:

**Environment**:
- EKS Anywhere Release: v0.11.3
- EKS Distro Release:

Start with the `eksa create packages` command and its `-f` path handling. Reproduce the failure using relative and absolute paths outside the current directory, then verify both forms succeed as they do from the parent directory.

Written by the indexing model from the issue text.