Make Bazel tests compatible with Starlark implementation of Python rules

Summary of changes:

* Remove usage of Python rules where not necessary; the Python rules
  were/are being used to test features that aren't specific to the Python
  rules.
* Use regex matching for failures instead of exact strings. The Starlark
  rules have slightly different phrasing or orderings of elements that
  don't affect behavior. This also makes the tests less brittle overall.
* Disable attempting to use the Starlark implementation in all the tests
  requiring Python 2 (e.g. srcs_version checking etc). The Starlark
  implementation doesn't currently (and probably never will) support Python
  2. https://github.com/bazelbuild/bazel/issues/15684 filed to track removal
  of it in Bazel.
* Disable attempting to use the Starlark implementation where toolchain
  resolution is required. This will eventually be implemented, but isn't
  is use at Google and otherwise blocks switching internally.
* Tests verifying warnings are printed were removed; Starlark doesn't
  provide a warning facility.
* Stamping is disabled in various tests because, with the Starlark implementation,
  it requires remote execution of actions, which some tests aren't setup for
  (they never needed it previously). Rather than set this up, stamping was
  disabled (affected tests don't require stamping anyways).

PiperOrigin-RevId: 455695015
Change-Id: I82822eff05b6c0a66e65f131c9e1c8784b1573ac
diff --git a/src/test/shell/integration/modify_execution_info_test.sh b/src/test/shell/integration/modify_execution_info_test.sh
index 28e485e..80c1d46 100755
--- a/src/test/shell/integration/modify_execution_info_test.sh
+++ b/src/test/shell/integration/modify_execution_info_test.sh
@@ -241,7 +241,7 @@
 Turbine=+requires-turbine,\
 JavaSourceJar=+requires-java-source-jar,\
 Javac=+requires-javac,\
-PyTinypar=+requires-py-tinypar,\
+Py.*=+requires-py,\
 Action=+requires-action \
    > output 2> "$TEST_log" || fail "Expected success"
 
@@ -260,9 +260,7 @@
   assert_contains "requires-java-source-jar: ''" output
   assert_contains "requires-proto: ''" output  # GenProtoDescriptorSet should match
   if [[ "$PRODUCT_NAME" != "bazel" ]]; then
-    # Python rules generate some cpp actions and local actions, but py-tinypar
-    # is the main unique-to-python rule which runs remotely for a py_binary.
-    assert_contains "requires-py-tinypar: ''" output
+    assert_contains "requires-py: ''" output
   fi
 }