hashi_vault - add AppRole deprecation and fix invalid deprecation logic

[briantist]

SUMMARY

Fixes #32

This started out just being a PR to use the newer hvac auth method class for AppRole, and add our deprecation fallback logic.

But I discovered that logic (which I put in place) only actually works on the positive case (the new auth method is available) and actually fails otherwise, so it was never working as intended 🤦‍♂️.

Took this opportunity to fix that, and make it more pythonic using exception handling instead of hasattr().

Tested with multiple versions of hvac locally to ensure it worked right (we don't [yet] test multiple hvac versions in CI).

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

hashi_vault.py

ADDITIONAL INFORMATION

[codecov]

Codecov Report

Merging #33 (d471b0a) into main (a4374fd) will decrease coverage by 0.48%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main      #33      +/-   ##
==========================================
- Coverage   64.15%   63.67%   -0.49%     
==========================================
  Files           1        1              
  Lines         226      234       +8     
  Branches       45       41       -4     
==========================================
+ Hits          145      149       +4     
- Misses         66       71       +5     
+ Partials       15       14       -1     

Impacted Files	Coverage Δ
...ommunity/hashi_vault/plugins/lookup/hashi_vault.py	63.67% <0.00%> (-0.49%)	⬇️

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