Remove InterpreterOptions plugin configuration option

The documentation for the `InterpreterOptions` plugin configuration
option is ambiguous - it implies the options within are used by Python
while the .pex is being built (e.g. while compiling bytecode), but
actually they're embedded in the .pex and used at run time. Now they
aren't used at all: this functionality is instead provided by
`RuntimeInterpreterArgs`.

Remove `InterpreterOptions`, since it is obsolete. Also tidy up some of
the variable names in the Python build defs to make it explicit that the
arguments in `RuntimeInterpreterArgs` are in fact passed to Python at
run time.

Author: chrisnovakovic

.plzconfig

@@ -53,12 +53,6 @@ DefaultValue = python3
 Inherit = true
 Help = The default Python interpreter to use when building .pex files.
 
-[PluginConfig "interpreter_options"]
-ConfigKey = InterpreterOptions
-Optional = true
-Repeatable = true
-Help = A list of additional arguments to pass to the Python interpreter when building .pex files.
-
 [PluginConfig "default_runtime_interpreters"]
 ConfigKey = DefaultRuntimeInterpreters
 Optional = true

build_defs/python.build_defs

@@ -153,13 +153,13 @@ def python_binary(name:str, main:str, srcs:list=[], resources:list=[], out:str=N
         test_only=test_only,
     )
 
-    interpreter_opts, interpreter_deps = _runtime_interpreter(interpreter, runtime_interpreters, runtime_interpreter_args)
+    runtime_args, runtime_targets = _runtime_interpreter(interpreter, runtime_interpreters, runtime_interpreter_args)
     zipsafe_flag = '' if zip_safe is False else '--zip_safe'
     cmd = '$TOOLS_PEX --preamble_verbosity="%s" -m "%s" %s %s' % (
         CONFIG.PYTHON.DEFAULT_PREAMBLE_VERBOSITY,
         module_dir,
         zipsafe_flag,
-        interpreter_opts,
+        runtime_args,
     )
 
     # If content hashing feature flag is enabled, we use the hash of the built
@@ -191,7 +191,7 @@ def python_binary(name:str, main:str, srcs:list=[], resources:list=[], out:str=N
         output_is_complete=True,
         tools={
             'interpreter': [interpreter],
-            'runtime_interpreters': interpreter_deps,
+            'runtime_interpreters': runtime_targets,
             'pex': [CONFIG.PYTHON.PEX_TOOL],
         },
         test_only=test_only,
@@ -207,7 +207,7 @@ def python_binary(name:str, main:str, srcs:list=[], resources:list=[], out:str=N
     return build_rule(
         name=name,
         srcs=[pex_rule],
-        runtime_deps=interpreter_deps,
+        runtime_deps=runtime_targets,
         deps=[lib_rule],
         outs=[out or (name + '.pex')],
         data=data,
@@ -291,12 +291,12 @@ def python_test(name:str, srcs:list, data:list|dict=[], resources:list=[], deps:
                          `unittest`, `pytest`, or a custom test runner entry point.
     """
     test_runner = test_runner or CONFIG.PYTHON.TEST_RUNNER
-    interpreter_opts, interpreter_deps = _runtime_interpreter(interpreter, runtime_interpreters, runtime_interpreter_args)
+    runtime_args, runtime_targets = _runtime_interpreter(interpreter, runtime_interpreters, runtime_interpreter_args)
     cmd = '$TOOLS_PEX --preamble_verbosity="%s" -t -m "%s" -r "%s" --zip_safe --add_test_runner_deps %s --stamp="$RULE_HASH"' % (
         CONFIG.PYTHON.DEFAULT_PREAMBLE_VERBOSITY,
         module_dir,
         test_runner,
-        interpreter_opts,
+        runtime_args,
     )
     if site:
         cmd += ' -S'
@@ -331,7 +331,7 @@ def python_test(name:str, srcs:list, data:list|dict=[], resources:list=[], deps:
         deps=deps,
         tools={
             'interpreter': [interpreter],
-            'runtime_interpreters': interpreter_deps,
+            'runtime_interpreters': runtime_targets,
             'pex': [CONFIG.PYTHON.PEX_TOOL],
         },
         labels = labels,
@@ -375,7 +375,7 @@ def python_test(name:str, srcs:list, data:list|dict=[], resources:list=[], deps:
     return build_rule(
         name=name,
         srcs=[pex_rule],
-        runtime_deps=interpreter_deps,
+        runtime_deps=runtime_targets,
         deps=deps,
         data=data,
         outs=[f'{name}.pex'],