chore: improve error message for py_runtime missing version info

[wade-arista]

When a python toolchain is added directly using py_runtime, etc, the interpreter_version_info attribute (a dict) is required.

Prior to this change, it would fail in e.g. _py_binary_rule_impl with an error:

Error: 'dict' value has no field or method 'major'

Check this in earlier in _resolve_toolchain where we find the "interpreter_version_info" attribute, ensuring that it has all of the required dict keys.

---

Test plan

Manual testing.

Error in fail: 
ERROR: In Bazel 7.x and later, the python toolchain py_runtime interpreter_version_info must be set to a dict with keys "major", "minor", and "micro".

`PyRuntimeInfo` requires that this field contains the static version information for the given
interpreter. This can be set via `py_runtime` when registering an interpreter toolchain, and will
done automatically for the builtin interpreter versions registered via `python_register_toolchains`.
Note that this only available on the Starlark implementation of the provider.

For example:

    py_runtime(
        name = "system_runtime",
        interpreter_path = "/usr/bin/python",
        interpreter_version_info = {
            "major": "3",
            "minor": "11",
            "micro": "6",
        },
        python_version = "PY3",
    )

From this toolchain definition:

load("@rules_python//python:defs.bzl", "py_runtime", "py_runtime_pair")

py_runtime(
    name = "container_py3_runtime",
    interpreter_path = "/usr/bin/python",
    # interpreter_version_info = {
    #     "major": "3",
    #     "minor": "11",
    #     "micro": "6",
    # },
    python_version = "PY3",
)

py_runtime_pair(
    name = "container_py_runtime_pair",
    py2_runtime = None,
    py3_runtime = ":container_py3_runtime",
)

toolchain(
    name = "container_py_toolchain",
    toolchain = ":container_py_runtime_pair",
    toolchain_type = "@bazel_tools//tools/python:toolchain_type",
)

[mattem]

Nice, thanks!