[release 1.27] Bump flannel version to v0.25.2

[thomasferrandiz]

Backport:#10146
Issue: #10219

[codecov]

Codecov Report

Attention: Patch coverage is 41.30435% with 27 lines in your changes are missing coverage. Please review.

Project coverage is 29.24%. Comparing base (2593230) to head (e5eea95).

Files	Patch %	Lines
pkg/agent/flannel/flannel.go	41.30%	17 Missing and 10 partials ⚠️

Additional details and impacted files

@@                Coverage Diff                @@
##           release-1.27   #10222       +/-   ##
=================================================
- Coverage         43.11%   29.24%   -13.87%     
=================================================
  Files               158      155        -3     
  Lines             16311    17183      +872     
=================================================
- Hits               7032     5025     -2007     
- Misses             8030    11166     +3136     
+ Partials           1249      992      -257     

Flag	Coverage Δ
e2etests	36.21% <48.71%> (-10.10%)	⬇️
inttests	0.46% <0.00%> (?)
unittests	?

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.