Issue 6693: partially fail restore if CSI snapshot is involved but CSI feature is not ready

[Lyndon-Li]

Fix issue #6693, partially fail restore if CSI snapshot is involved but CSI feature is not ready, i.e., CSI feature gate is not enabled or CSI plugin is not installed.

[codecov]

Codecov Report

Merging #7077 (efc5319) into main (cb5ffe2) will increase coverage by 0.05%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##             main    #7077      +/-   ##
==========================================
+ Coverage   61.16%   61.22%   +0.05%     
==========================================
  Files         256      257       +1     
  Lines       27222    27259      +37     
==========================================
+ Hits        16650    16688      +38     
+ Misses       9389     9388       -1     
  Partials     1183     1183              

Files	Coverage Δ
pkg/restore/restore.go	66.87% <100.00%> (+0.79%)	⬆️
pkg/plugin/clientmgmt/process/registry.go	25.71% <0.00%> (-0.57%)	⬇️
pkg/cmd/server/server.go	21.62% <0.00%> (-0.06%)	⬇️
pkg/features/verify.go	77.77% <77.77%> (ø)