[flaky] test/h2c-client.js

test at test/h2c-client.js:86:1
✖ Should reject request if not h2c supported (165.512917ms)
  Error: error:068000DD:asn1 encoding routines::illegal padding
      at node:internal/tls/secure-context:70:13
      at Array.forEach (<anonymous>)
      at setCerts (node:internal/tls/secure-context:68:3)
      at configSecureContext (node:internal/tls/secure-context:191:5)
      at Object.createSecureContext (node:internal/tls/common:113:3)
      at Server.setSecureContext (node:internal/tls/wrap:1512:27)
      at new Server (node:internal/tls/wrap:1376:8)
      at new Http2SecureServer (node:internal/http2/core:3390:5)
      at createSecureServer (node:internal/http2/core:3604:10)
      at TestContext.<anonymous> (/Users/runner/work/undici/undici/test/h2c-client.js:89:18) {
    opensslErrorStack: [ 'error:0488000D:PEM routines::ASN1 lib', 'error:0688010A:asn1 encoding routines::nested asn1 error', 'error:0688010A:asn1 encoding routines::nested asn1 error' ],
    library: 'asn1 encoding routines',
    reason: 'illegal padding',
    code: 'ERR_OSSL_ASN1_ILLEGAL_PADDING'
  }

Example: https://github.com/nodejs/undici/actions/runs/24710844416/job/72274863307

Start with test/h2c-client.js at line 86 and inspect the createSecureServer setup around line 89. Run the failing test and compare the expected h2c rejection with the TLS parsing error shown in the report. Done means the test runs reliably and checks the intended rejection without the certificate setup failing first.