fix(secrets): use NewEventsFromSlice function to handle both secrets and repo AllowEvents

[ecrupper]

Previously only repo had support for AllowEvents. But with go-vela/types#366, we can add support for both repo and secrets pretty easily.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.00%. Comparing base (379fce6) to head (d4b662b).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #543      +/-   ##
==========================================
- Coverage   82.09%   82.00%   -0.09%     
==========================================
  Files         147      147              
  Lines        3635     3584      -51     
==========================================
- Hits         2984     2939      -45     
+ Misses        480      474       -6     
  Partials      171      171              

Files	Coverage Δ
action/repo/add.go	94.28% <100.00%> (+3.17%)	⬆️
action/repo/update.go	100.00% <100.00%> (ø)
action/secret/add.go	83.33% <100.00%> (+0.47%)	⬆️
action/secret/update.go	83.33% <100.00%> (+0.47%)	⬆️
command/repo/add.go	93.10% <ø> (ø)
command/repo/update.go	93.10% <ø> (ø)
command/secret/add.go	75.00% <ø> (ø)
command/secret/update.go	75.00% <ø> (ø)