[6.4.0] Do not allow applicable_licenses on platform. (#19426)

RELNOTES:
`applicable_licenses` is no longer allowed on the `platform` rule.
Additionally, `default_package_metadata` from any `package` rule will
not be applied. PiperOrigin-RevId: 529808047
Change-Id: I7c2c682055bde6924d68858d38ef63f32457cdb9

Co-authored-by: Googler <aiuto@google.com>

src/main/java/com/google/devtools/build/lib/rules/platform/PlatformBaseRule.java

@@ -21,7 +21,6 @@
 import com.google.devtools.build.lib.analysis.PlatformConfiguration;
 import com.google.devtools.build.lib.analysis.RuleDefinition;
 import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
-import com.google.devtools.build.lib.packages.BuildType;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.RuleClass.ToolchainResolutionMode;
 import com.google.devtools.build.lib.packages.Type;
@@ -42,13 +41,7 @@ public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env)
                 // No need to show up in ":all", etc. target patterns.
                 .value(ImmutableList.of("manual"))
                 .nonconfigurable("low-level attribute, used in platform configuration"))
-        .override(
-            // A platform is essentially a constant which is never linked into a target.
-            // This will, in a very hacky way, suppress picking up default_applicable_licenses
-            attr("applicable_licenses", BuildType.LABEL_LIST)
-                .value(ImmutableList.of())
-                .allowedFileTypes()
-                .nonconfigurable("fundamental constant, used in platform configuration"))
+        .removeAttribute("applicable_licenses")
         .exemptFromConstraintChecking("this rule helps *define* a constraint")
         .useToolchainResolution(ToolchainResolutionMode.DISABLED)
         .removeAttribute("deps")