Updating scep package with latest fixes

[getvictor]

Updating scep package with changes up to github.com/micromdm/scep@781f8042a79cabcf61a5e6c01affdbadcb785932
Fixes needed for NDES client for #21955

Manually pulled in the recent changes. You can view the changes in the remote like:
getvictor/scep@fleet...micromdm:scep:main

[getvictor]

@roperzh Assigning the review to you since this might impact MDM SCEP

[codecov]

Codecov Report

Attention: Patch coverage is 45.45455% with 54 lines in your changes missing coverage. Please review.

Project coverage is 65.20%. Comparing base (ea0175e) to head (1c12fbc).
Report is 13 commits behind head on main.

Files with missing lines	Patch %	Lines
server/mdm/scep/depot/file/depot.go	19.23%	20 Missing and 1 partial ⚠️
server/mdm/scep/cmd/scepclient/scepclient.go	0.00%	20 Missing ⚠️
server/mdm/scep/depot/signer.go	37.50%	4 Missing and 1 partial ⚠️
server/mdm/scep/cmd/scepserver/scepserver.go	0.00%	3 Missing ⚠️
server/mdm/scep/csrverifier/csrverifier.go	0.00%	3 Missing ⚠️
server/mdm/scep/cmd/scepclient/csr.go	0.00%	1 Missing ⚠️
server/mdm/scep/depot/bolt/depot.go	93.75%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #22372      +/-   ##
==========================================
+ Coverage   65.17%   65.20%   +0.02%     
==========================================
  Files        1496     1494       -2     
  Lines      117013   116839     -174     
  Branches     3573     3573              
==========================================
- Hits        76265    76185      -80     
+ Misses      33623    33574      -49     
+ Partials     7125     7080      -45     

Flag	Coverage Δ
backend	66.48% <45.45%> (+0.03%)	⬆️

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.

[roperzh]

thank you! can spot anything that might break, but this is "easy" to test and will be thoroughly covered by regular QA