Deprecated AWS settings should be DeprecatedWarning (elastic#127861)

We deprecated various settings during the upgrades to AWS SDK v2 with
the intention of removing them in 10.0.0, but this means that they are
not critically deprecated in the backport to 8.19.x since they will
continue to work in the 9.x series too. This commit downgrades these
settings from `Deprecated` to `DeprecatedWarning` in the `8.19` branch.

Author: DaveCTurner

modules/repository-s3/src/main/java/org/elasticsearch/repositories/s3/S3ClientSettings.java

@@ -82,7 +82,13 @@ final class S3ClientSettings {
     static final Setting.AffixSetting<HttpScheme> PROTOCOL_SETTING = Setting.affixKeySetting(
         PREFIX,
         "protocol",
-        key -> new Setting<>(key, "https", s -> HttpScheme.valueOf(s.toUpperCase(Locale.ROOT)), Property.NodeScope, Property.Deprecated)
+        key -> new Setting<>(
+            key,
+            "https",
+            s -> HttpScheme.valueOf(s.toUpperCase(Locale.ROOT)),
+            Property.NodeScope,
+            Property.DeprecatedWarning
+        )
     );
 
     /** The host name of a proxy to connect to s3 through. */
@@ -145,7 +151,7 @@ final class S3ClientSettings {
     static final Setting.AffixSetting<Boolean> UNUSED_USE_THROTTLE_RETRIES_SETTING = Setting.affixKeySetting(
         PREFIX,
         "use_throttle_retries",
-        key -> Setting.boolSetting(key, true, Property.NodeScope, Property.Deprecated)
+        key -> Setting.boolSetting(key, true, Property.NodeScope, Property.DeprecatedWarning)
     );
 
     /** Whether the s3 client should use path style access. */
@@ -173,7 +179,7 @@ final class S3ClientSettings {
     static final Setting.AffixSetting<String> UNUSED_SIGNER_OVERRIDE = Setting.affixKeySetting(
         PREFIX,
         "signer_override",
-        key -> Setting.simpleString(key, Property.NodeScope, Property.Deprecated)
+        key -> Setting.simpleString(key, Property.NodeScope, Property.DeprecatedWarning)
     );
 
     /** Credentials to authenticate with s3. */

plugins/discovery-ec2/src/main/java/org/elasticsearch/discovery/ec2/Ec2ClientSettings.java

@@ -67,7 +67,7 @@ final class Ec2ClientSettings {
         "https",
         s -> HttpScheme.valueOf(s.toUpperCase(Locale.ROOT)),
         Property.NodeScope,
-        Property.Deprecated
+        Property.DeprecatedWarning
     );
 
     /** The username of a proxy to connect to EC2 through. */