fix: allows podInfo.Cluster to be empty

[dspo]

What type of this PR

Add one of the following kinds:
/kind bugfix

What this PR does / why we need it:

Fixed the problem of inaccurate project resource request value

Which issue(s) this PR fixes:

• Fixes #your-issue_number
• [Erda Cloud Issue Link](paste your link here)

Specified Reviewers:

/assign @your-reviewer

ChangeLog

Language	Changelog
🇺🇸 English
🇨🇳 中文

Need cherry-pick to release versions?

Add comment like /cherry-pick release/1.0 when this PR is merged.

For details on the cherry pick process, see the cherry pick requests section under CONTRIBUTING.md.

[codecov]

Codecov Report

Merging #3398 (d812135) into master (153fb4b) will not change coverage.
The diff coverage is 66.66%.

@@           Coverage Diff           @@
##           master    #3398   +/-   ##
=======================================
  Coverage   18.00%   18.00%           
=======================================
  Files        1403     1403           
  Lines      145392   145392           
=======================================
  Hits        26175    26175           
  Misses     116525   116525           
  Partials     2692     2692           

Impacted Files	Coverage Δ
modules/core-services/services/project/project.go	15.77% <0.00%> (ø)
modules/core-services/services/project/cache.go	69.23% <100.00%> (ø)

[luobily]

/approve