bazel packages: move BazelStarlarkContext here

Previously, it was in package lib.analysis.starlark,
which package was split into two java_library build rules
with other packages sandwiched in between.
There are no valid reasons ever to do that.

Also, remove unnecessary dependency from skydoc.

PiperOrigin-RevId: 267206351
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
index d4e3e0d..47cf7e3 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
@@ -58,7 +58,6 @@
 import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget.Mode;
 import com.google.devtools.build.lib.analysis.constraints.ConstraintSemantics;
 import com.google.devtools.build.lib.analysis.platform.PlatformInfo;
-import com.google.devtools.build.lib.analysis.skylark.SymbolGenerator;
 import com.google.devtools.build.lib.analysis.stringtemplate.TemplateContext;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.RepositoryName;
@@ -90,6 +89,7 @@
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.RuleErrorConsumer;
+import com.google.devtools.build.lib.packages.SymbolGenerator;
 import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.packages.TargetUtils;
 import com.google.devtools.build.lib.skyframe.ConfiguredTargetAndData;