Regard DSP as done only when preparation is successful considering of reuse the provider

[ffjlabo]

What this PR does / why we need it:

This modification is necessary to avoid an error when executing a cancellation while executing deploySourceProvider.Get in another stage.

I encountered such a situation when canceling the deployment via WebUI during the SCRIPT_RUN stage execution.
I reproduced the behavior when checking the behavior for the PR #5215 like this↓

Which issue(s) this PR fixes:

Part of #5214

Does this PR introduce a user-facing change?:

• How are users affected by this change:
• Is this breaking change:
• How to migrate (if breaking change):

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 22.83%. Comparing base (5d3e17d) to head (f87754a).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/app/piped/deploysource/deploysource.go	0.00%	2 Missing ⚠️
pkg/app/pipedv1/deploysource/deploysource.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #5216   +/-   ##
=======================================
  Coverage   22.82%   22.83%           
=======================================
  Files         420      420           
  Lines       45302    45302           
=======================================
+ Hits        10340    10344    +4     
+ Misses      34166    34163    -3     
+ Partials      796      795    -1     

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[khanhtc1202]

Nice catch, thank you 👍

[t-kikuc]

[ASK] How about the following point?

pipecd/pkg/app/piped/deploysource/deploysource.go

Line 117 in 6b004fa

p.done = true

[ffjlabo]

@t-kikuc Thank you! This also might lead to the same error. So I fixed it 🙏 f87754a

[t-kikuc]

thank you!

[Warashi]

thank you