fix: add missing clientCertificate type to ResolvedConfigOptions (#18028)

Co-authored-by: Lachlan Miller <lachlan.miller.1990@outlook.com>

cli/types/cypress.d.ts

@@ -2488,6 +2488,47 @@ declare namespace Cypress {
     cmdKey: boolean
   }
 
+  interface PEMCert {
+    /**
+     * Path to the certificate file, relative to project root.
+     */
+    cert: string
+    /**
+     * Path to the private key file, relative to project root.
+     */
+    key: string
+    /**
+     * Path to a text file containing the passphrase, relative to project root.
+     */
+    passphrase?: string
+  }
+
+  interface PFXCert {
+    /**
+     * Path to the certificate container, relative to project root.
+     */
+    pfx: string
+    /**
+     * Path to a text file containing the passphrase, relative to project root.
+     */
+    passphrase?: string
+  }
+
+  interface ClientCertificate {
+    /**
+     * URL to match requests against. Wildcards following [minimatch](https://github.com/isaacs/minimatch) rules are supported.
+     */
+    url: string
+    /**
+     * Paths to one or more CA files to validate certs against, relative to project root.
+     */
+    ca?: string[]
+    /**
+     * A PEM format certificate/private key pair or PFX certificate container
+     */
+    certs: PEMCert[] | PFXCert[]
+  }
+
   interface ResolvedConfigOptions {
     /**
      * Url used as prefix for [cy.visit()](https://on.cypress.io/visit) or [cy.request()](https://on.cypress.io/request) command’s url
@@ -2750,6 +2791,11 @@ declare namespace Cypress {
      * @default {}
      */
     e2e: Omit<ResolvedConfigOptions, TestingType>
+
+    /**
+     * An array of objects defining the certificates
+     */
+    clientCertificates: ClientCertificate[]
   }
 
   /**