bugfix(cliconfig.go): emit a warning msg if invalid CLI configuration file location

[rkhaled0]

This Pull Request is about noticing people when TF_CLI_CONFIG_FILE environment variable points to a non existing file.

In such case, a warning message will be printed out like below;

There are some problems with the CLI configuration:
╷
│ Warning: Unable to open CLI configuration file
│
│ The CLI configuration file at
│ "/private/var/folders/7b/q4m7dd2x4fl8ltp731djsw940000gn/T/tmp.5TVZNsJu/.terraform.rcr"
│ specified does not exist.
╵

Fixes #32646

Target Release

1.4.x

Draft CHANGELOG entry

BUG FIXES

• When setting an invalid CLI configuration file location, emit a warning message

[crw]

Thanks for this submission!

[jbardin]

Thanks @rkhaled0, rebased and merged in #32846

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active contributions.
If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.