Remove superfluous, unused line in .bazelrc

We have completed the Python migration a while ago. No point in
keeping this config around. The platforms don't exist anymore.

Signed-off-by: Philipp Schrader <philipp.schrader@gmail.com>
Change-Id: Iae15a38931e4487860705ab431365b0e07643df6
diff --git a/.bazelrc b/.bazelrc
index 9ff6c55..261f4c5 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -22,7 +22,6 @@
 
 # Shortcuts for selecting the target platform.
 build:k8 --platforms=//tools/platforms:linux_x86
-build:k8_legacy_python --platforms=//tools/platforms:linux_x86_legacy_python --host_platform=//tools/platforms:linux_x86_legacy_python
 build:roborio --platforms=//tools/platforms:linux_roborio
 build:roborio --platform_suffix=-roborio
 build:arm64 --platforms=//tools/platforms:linux_arm64