fix runtime error when sso token expires

[shwethaumashanker]

What changed?

Added nil pointer handling

Why?

Requesting access with a expired SSO token gave the following error:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x0 pc=0x100989ba4]

goroutine 1 [running]:
gopkg.in/ini%2ev1.(*Section).GetKey(0x0, {0x100b1fddd?, 0x16f8aaf6f?})
        /Users/runner/go/pkg/mod/gopkg.in/ini.v1@v1.67.0/section.go:109 +0x24
github.com/common-fate/granted/pkg/cfaws.(*Profile).SSOScopes(0x16f8aaf6f?)

How did you test it?

Locally reproduced the error and tested that the fix works.
How to test:

• Delete sso token
• run assume --sso --sso-start-url https://qwertyui.awsapps.com/start --sso-region ap-southeast-2 --account-id 123456789 --role-name AdministratorAccess (This will give error)
• run dassume --sso --sso-start-url https://qwertyui.awsapps.com/start --sso-region ap-southeast-2 --account-id 123456789 --role-name AdministratorAccess (fix)

Potential risks

Is patch release candidate?

Link to relevant docs PRs