Remove the deprecated isToolchainEnabled method.

PiperOrigin-RevId: 281067275

src/main/java/com/google/devtools/build/lib/analysis/PlatformConfiguration.java

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/PlatformConfiguration.java b/src/main/java/com/google/devtools/build/lib/analysis/PlatformConfiguration.java
index d7b32fb..756fb44 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/PlatformConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/PlatformConfiguration.java
@@ -90,10 +90,6 @@
     return enabledToolchainTypes;
   }
 
-  public boolean isToolchainTypeEnabled(Label toolchainType) {
-    return getEnabledToolchainTypes().contains(toolchainType);
-  }
-
   /**
    * Returns a list of labels referring to additional constraint value targets which should be taken
    * into account when resolving the toolchains/execution platform for the target with the given

src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
index 063809f..e9ed525 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
@@ -39,7 +39,6 @@
 import com.google.devtools.build.lib.analysis.AnalysisUtils;
 import com.google.devtools.build.lib.analysis.Expander;
 import com.google.devtools.build.lib.analysis.FileProvider;
-import com.google.devtools.build.lib.analysis.PlatformConfiguration;
 import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
 import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.Runfiles;
@@ -987,14 +986,7 @@
         Preconditions.checkNotNull(
             ruleContext.getConfiguration().getOptions().get(CppOptions.class));
 
-    if (cppOptions.enableCcToolchainResolution) {
-      return true;
-    }
-
-    // TODO(https://github.com/bazelbuild/bazel/issues/7260): Remove this and the flag.
-    PlatformConfiguration platformConfig =
-        Preconditions.checkNotNull(ruleContext.getFragment(PlatformConfiguration.class));
-    return platformConfig.isToolchainTypeEnabled(getToolchainTypeFromRuleClass(ruleContext));
+    return cppOptions.enableCcToolchainResolution;
   }
 
   public static ImmutableList<CcCompilationContext> getCompilationContextsFromDeps(