feat: add ability to pass user flags to python interpreter

Author: muravev-vasilii

docs/py_binary.md

@@ -68,7 +68,7 @@ def _py_binary_rule_impl(ctx):
         output = executable_launcher,
         substitutions = {
             "{{BASH_RLOCATION_FN}}": BASH_RLOCATION_FUNCTION,
-            "{{INTERPRETER_FLAGS}}": " ".join(py_toolchain.flags),
+            "{{INTERPRETER_FLAGS}}": " ".join(py_toolchain.flags + ctx.attr.interpreter_options),
             "{{VENV_TOOL}}": to_rlocation_path(ctx, venv_toolchain.bin),
             "{{ARG_COLLISION_STRATEGY}}": ctx.attr.package_collisions,
             "{{ARG_PYTHON}}": to_rlocation_path(ctx, py_toolchain.python) if py_toolchain.runfiles_interpreter else py_toolchain.python.path,
@@ -149,6 +149,10 @@ A collision can occour when multiple packages providing the same file are instal
         default = "error",
         values = ["error", "warning", "ignore"],
     ),
+    "interpreter_options": attr.string_list(
+        doc = "Additional options to pass to the Python interpreter in addition to -B and -I passed by rules_py",
+        default = [],
+    ),
     "_run_tmpl": attr.label(
         allow_single_file = True,
         default = "//py/private:run.tmpl.sh",