Merge pull request #51892 from zk-123/patch-1

fix: grammatical error bug

Author: k8s-ci-robot

content/en/docs/reference/access-authn-authz/certificate-signing-requests.md

@@ -124,7 +124,7 @@ This includes:
    when usages different than the signer-determined usages are specified in the CSR.
 1. **Expiration/certificate lifetime**: whether it is fixed by the signer, configurable by the admin, determined by the CSR `spec.expirationSeconds` field, etc
    and the behavior when the signer-determined expiration is different from the CSR `spec.expirationSeconds` field.
-1. **CA bit allowed/disallowed**: and behavior if a CSR contains a request a for a CA certificate when the signer does not permit it.
+1. **CA bit allowed/disallowed**: and behavior if a CSR contains a request for a CA certificate when the signer does not permit it.
 
 Commonly, the `status.certificate` field of a CertificateSigningRequest contains a
 single PEM-encoded X.509 certificate once the CSR is approved and the certificate is issued.