ci: remove py2-rust support

Nobody cares about this very narrow usecase, and py2 support is over by
July 1st. This helps with the CI load, and removes some flakiness.

contrib/heptapod-ci.yml

@@ -41,19 +41,12 b' checks-py3:'
         RUNTEST_ARGS: "--time --test-list /tmp/check-tests.txt"
         PYTHON: python3
 
-rust-cargo-test-py2: &rust_cargo_test
-    <<: *all
+rust-cargo-test-py3:
     stage: tests
     script:
         - echo "python used, $PYTHON"
         - make rust-tests
 
-rust-cargo-test-py3:
-    stage: tests
-    <<: *rust_cargo_test
-    variables:
-        PYTHON: python3
-
 phabricator-refresh:
     stage: phabricator
     rules:
@@ -100,13 +93,6 b' test-py3-pure:'
         PYTHON: python3
         TEST_HGMODULEPOLICY: "py"
 
-test-py2-rust:
-    <<: *runtests
-    variables:
-        HGWITHRUSTEXT: cpython
-        RUNTEST_ARGS: "--rust --blacklist /tmp/check-tests.txt"
-        TEST_HGMODULEPOLICY: "rust+c"
-
 test-py3-rust:
     <<: *runtests
     variables: