Correct purpose setting for OCSP_request_verify

[samuel40791765]

Fixes a logic error from && → || in OCSP_request_verify when initializing the store context and setting its purpose. With &&, a set_purpose failure is silently ignored when init succeeds, so X509_verify_cert runs without X509_PURPOSE_OCSP_HELPER.

OCSP_HELPER is already intentionally permissive (skips leaf EKU checks, uses basic self-signed root trust), and the default path without it behaves nearly the same way. The signature is already validated before this point.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.18%. Comparing base (32bba49) to head (f369d06).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
crypto/ocsp/ocsp_verify.c	75.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3089      +/-   ##
==========================================
- Coverage   78.19%   78.18%   -0.02%     
==========================================
  Files         689      689              
  Lines      121814   121822       +8     
  Branches    16995    16994       -1     
==========================================
- Hits        95254    95246       -8     
- Misses      25676    25689      +13     
- Partials      884      887       +3     

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[justsmth]

NP: We could also make these success values explicit:

    if (1 != X509_STORE_CTX_init(ctx, store, signer, NULL) ||
        1 != X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_OCSP_HELPER)) {

[WillChilds-Klein]

should we error if this fails?