fix(store/valkey): Redis™ Sentinel doesn't require a password

Signed-off-by: Xe Iaso <me@xeiaso.net>

docs/docs/admin/policies.mdx

@@ -326,7 +326,7 @@ If you are using [Redis™ Sentinel](https://redis.io/docs/latest/operate/oss_an
 | `clientName` | string                   | `Anubis`              | The client name reported to Redis™ Sentinel. Set this if you want to track Anubis connections to your Redis™ Sentinel.                                    |
 | `masterName` | string                   | `mymaster`            | (Required) The name of the master in the Redis™ Sentinel configuration. This is used to discover where to find client connection hosts/ports.             |
 | `username`   | string                   | `azurediamond`        | The username used to authenticate against the Redis™ Sentinel and Redis™ servers.                                                                         |
-| `password`   | string                   | `hunter2`             | (Required) The password used to authenticate against the Redis™ Sentinel and Redis™ servers.                                                              |
+| `password`   | string                   | `hunter2`             | The password used to authenticate against the Redis™ Sentinel and Redis™ servers.                                                                         |
 
 ## Risk calculation for downstream services
 

lib/store/valkey/factory.go

@@ -24,7 +24,6 @@ var (
 	// Sentinel validation errors
 	ErrSentinelMasterNameRequired = errors.New("valkey.Sentinel: masterName is required")
 	ErrSentinelAddrRequired       = errors.New("valkey.Sentinel: addr is required")
-	ErrSentinelPasswordRequired   = errors.New("valkey.Sentinel: password is required")
 	ErrSentinelAddrEmpty          = errors.New("valkey.Sentinel: addr cannot be empty")
 )
 
@@ -68,7 +67,7 @@ type Sentinel struct {
 	Addr       internal.ListOr[string] `json:"addr"`
 	ClientName string                  `json:"clientName,omitempty"`
 	Username   string                  `json:"username,omitempty"`
-	Password   string                  `json:"password"`
+	Password   string                  `json:"password,omitempty"`
 }
 
 func (s Sentinel) Valid() error {
@@ -94,10 +93,6 @@ func (s Sentinel) Valid() error {
 		}
 	}
 
-	if s.Password == "" {
-		errs = append(errs, ErrSentinelPasswordRequired)
-	}
-
 	if len(errs) > 0 {
 		return errors.Join(errs...)
 	}

lib/store/valkey/valkey_test.go

@@ -91,7 +91,7 @@ func TestFactoryValid(t *testing.T) {
 		{
 			name:        "sentinel missing password",
 			jsonData:    `{"sentinel": {"masterName": "mymaster", "addr": ["localhost:26379"]}}`,
-			expectError: ErrSentinelPasswordRequired,
+			expectError: nil,
 		},
 		{
 			name:        "sentinel with optional fields",