openroad.bzl: remove unused orfs_version attribute

Signed-off-by: Pawel Czarnecki <[email protected]>

openroad.bzl

@@ -124,7 +124,6 @@ def build_openroad(
         stage_args = {},
         mock_abstract = False,
         mock_stage = "place",
-        orfs_version = 4,
         mock_area = None,
         platform = "asap7",
         macro_variant = "base"):
@@ -142,7 +141,6 @@ def build_openroad(
       stage_args: dictionary keyed by ORFS stages with lists of stage-specific arguments
       mock_abstract: boolean controling the scope of _generate_abstract stage
       mock_stage: string with physical design flow stage name which controls the name of the files generated in _generate_abstract stage
-      orfs_version: <UNUSED> integer specifying ORFS version, sets ORFS_VERSION env var
       mock_area: floating point number, spawns additional _mock_area targets if set
       platform: string specifying target platform for running physical design flow. Supported platforms: https://openroad-flow-scripts.readthedocs.io/en/latest/user/FlowVariables.html#platform
       macro_variant: variant of the ORFS flow the macro was built with
@@ -230,7 +228,6 @@ def build_openroad(
 
     base_args = [
         "WORK_HOME=$(RULEDIR)",
-        "ORFS_VERSION=" + str(orfs_version),
         "DESIGN_NAME=" + name,
         "FLOW_VARIANT=" + variant,
         "DESIGN_CONFIG=$(location " + str(Label("//:config.mk")) + ")",