providers/redfish: fixes a panic in cases where a nil bios object was returned

[joelrebel]

What does this PR implement/change/remove?

Fixes a nil panic in Redfish BIOS data queries.

Checklist

• Tests added
  • The redfish mock code could use some work so that tests can check for non-happy cases, at the moment its not trivial to implement tests for those conditions.
• Similar commits squashed

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.04 ⚠️

Comparison is base (44558f0) 43.31% compared to head (ef401f6) 43.28%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #317      +/-   ##
==========================================
- Coverage   43.31%   43.28%   -0.04%     
==========================================
  Files          35       35              
  Lines        2731     2733       +2     
==========================================
  Hits         1183     1183              
- Misses       1426     1427       +1     
- Partials      122      123       +1     

Impacted Files	Coverage Δ
providers/redfish/bios.go	50.00% <0.00%> (-7.15%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.