tests: update agilebits_com_valid cert/chain

The existing `agilebits.com` end-entity cert expired on Nov 15 2023.
This commit replaces it with an updated copy fetched from agilebits.com
that expires Oct 16 2024. Additionally, the chain of intermediates no
longer matches the ones used by `1password.com`, so we add the required
intermediates and remove the "SHARED_CHAIN" bits from the realworld
verification tests.

Author: cpu

src/tests/verification_real_world/agilebits_com_valid_1.crt

@@ -46,14 +46,6 @@ use crate::tests::assert_cert_error_eq;
 use rustls::{CertificateError, Error as TlsError};
 use std::convert::TryFrom;
 
-const SHARED_CHAIN: &[&[u8]] = &[
-    include_bytes!("1password_com_valid_2.crt"),
-    include_bytes!("1password_com_valid_3.crt"),
-    // XXX: This certificate is included for testing in environments that might need
-    // a cross-signed root certificate instead of the just the server-provided one.
-    include_bytes!("1password_com_valid_4.crt"),
-];
-
 // This is the certificate chain presented by one server for
 // my.1password.com when this test was updated 2022-09-22. It is
 // valid for *.1password.com and 1password.com from
@@ -67,22 +59,22 @@ const SHARED_CHAIN: &[&[u8]] = &[
 // You can update the cert file with `update_valid_1_cert.bash`
 const VALID_1PASSWORD_COM_CHAIN: &[&[u8]] = &[
     include_bytes!("1password_com_valid_1.crt"),
-    SHARED_CHAIN[0],
-    SHARED_CHAIN[1],
-    SHARED_CHAIN[2],
+    include_bytes!("1password_com_valid_2.crt"),
+    include_bytes!("1password_com_valid_3.crt"),
+    // XXX: This certificate is included for testing in environments that might need
+    // a cross-signed root certificate instead of the just the server-provided one.
+    include_bytes!("1password_com_valid_4.crt"),
 ];
 
 const MY_1PASSWORD_COM: &str = "my.1password.com";
 
 // A domain name for which `VALID_1PASSWORD_COM_CHAIN` isn't valid.
 const VALID_UNRELATED_DOMAIN: &str = "agilebits.com";
-// The chain is the same as `VALID_1PASSWORD_COM_CHAIN` except the
-// end-entity certificate is different.
 const VALID_UNRELATED_CHAIN: &[&[u8]] = &[
     include_bytes!("agilebits_com_valid_1.crt"),
-    SHARED_CHAIN[0],
-    SHARED_CHAIN[1],
-    SHARED_CHAIN[2],
+    include_bytes!("agilebits_com_valid_2.crt"),
+    include_bytes!("agilebits_com_valid_3.crt"),
+    include_bytes!("agilebits_com_valid_4.crt"),
 ];
 
 macro_rules! real_world_test_cases {