Update certificate lifetime defaults.

As of cockroachdb/cockroach#15306, the default
certificate lifetime is 10 years for all certificate types.

Author: marc

create-security-certificates.md

@@ -82,7 +82,7 @@ Flag | Description
 `--ca-key` | The path to the private key protecting the CA certificate. <br><br>This flag is required for all `create-*` subcommands. When used with `create-ca` in particular, it defines where to create the CA key; the specified directory must exist.<br><br>**Env Variable:** `COCKROACH_CA_KEY`
 `--allow-ca-key-reuse` | When running the `create-ca` subcommand, pass this flag to re-use an existing CA key identified by `--ca-key`. Otherwise, a new CA key will be generated.<br><br>This flag is used only by the `create-ca` subcommand. It helps avoid accidentally re-using an existing CA key.
 `--overwrite` | When running `create-*` subcommands, pass this flag to allow existing files in the certificate directory (`--certs-dir`) to be overwritten.<br><br>This flag helps avoid accidentally overwriting sensitive certificates and keys.
-`--lifetime` | The lifetime of the certificate, in hours, minutes, and seconds. <br><br>Certificates are valid from the time they are created through the duration specified in `--lifetime`.<br><br>**Default:** `43800h0m0s` (5 years) for the CA certificate, and `8760h0m0s` (1 year) for node and client certificates
+`--lifetime` | The lifetime of the certificate, in hours, minutes, and seconds. <br><br>Certificates are valid from the time they are created through the duration specified in `--lifetime`.<br><br>**Default:** `87840h0m0s` (10 years)
 `--key-size` | The size of the CA, node, or client key, in bits.<br><br>**Default:** `2048`