Remove redfish-use-3-digit-messageid

redfish-use-3-digit-messageid stated it would be removed in 2Q25, it is
now 4Q25. Searching OpenBMC doesn't show any users of this option.

This option was added in December 2014 and fixed a bug with us not
following the Redfish Spec.[1]

[1]: https://gerrit.openbmc.org/c/openbmc/bmcweb/+/76180

Tested: This is a pretty straightforward removal. Inspection and build
only.

Change-Id: I8a103d42184c21f75db19d44d8004f54d3fae01a
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/config/meson.build b/config/meson.build
index 61478e9..7e4b6f8 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -36,7 +36,6 @@
     'redfish-oem-manager-fan-data',
     'redfish-provisioning-feature',
     'redfish-updateservice-use-dbus',
-    'redfish-use-3-digit-messageid',
     'redfish-use-hardcoded-system-location-indicator',
     'rest',
     'session-auth',
diff --git a/meson.options b/meson.options
index bf44d11..360ab8d 100644
--- a/meson.options
+++ b/meson.options
@@ -25,17 +25,6 @@
                     https://github.com/openbmc/jsnbd/blob/master/README.''',
 )
 
-option(
-    'redfish-use-3-digit-messageid',
-    type: 'feature',
-    value: 'disabled',
-    description: '''Prior to a bug fix, bmcweb exposed error messages with a
-                    MessageId of Base.x.y.z.Message which was incorrect.
-                    Enabling this option causes return codes to return the old
-                    incorrect version for backward compatibility.  Will be
-                    removed Q2-2025''',
-)
-
 # BMCWEB_NBDPROXY
 # if you use this option and are seeing this comment, please comment here:
 # https://github.com/openbmc/bmcweb/issues/188 and put forward your intentions
diff --git a/redfish-core/include/registries.hpp b/redfish-core/include/registries.hpp
index f7a8df3..c9313ef 100644
--- a/redfish-core/include/registries.hpp
+++ b/redfish-core/include/registries.hpp
@@ -120,19 +120,9 @@
     {
         jArgs.push_back(arg);
     }
-    std::string msgId;
-    if (BMCWEB_REDFISH_USE_3_DIGIT_MESSAGEID)
-    {
-        msgId = std::format("{}.{}.{}.{}.{}", header.registryPrefix,
-                            header.versionMajor, header.versionMinor,
-                            header.versionPatch, entry.first);
-    }
-    else
-    {
-        msgId =
-            std::format("{}.{}.{}.{}", header.registryPrefix,
-                        header.versionMajor, header.versionMinor, entry.first);
-    }
+    std::string msgId =
+        std::format("{}.{}.{}.{}", header.registryPrefix, header.versionMajor,
+                    header.versionMinor, entry.first);
     nlohmann::json::object_t response;
     response["@odata.type"] = "#Message.v1_1_1.Message";
     response["MessageId"] = std::move(msgId);