Avoid key validation if validation is disabled

[fjetter]

This breaks off #8797

another small perf fix I encountered for very large graphs (only a couple percent of CPU time but still unnecessary). We typically disable validation and at this point I don't see a reason why this should be enabled at runtime.

This check essentially validates that all "keys" are of type {bytes, int, float, str} or a tuple that is made of those types.

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

    29 files  ±0      29 suites  ±0   12h 1m 19s ⏱️ + 5m 17s
 4 102 tests ±0   3 984 ✅  - 4    111 💤 ±0   7 ❌ + 4 
55 493 runs  ±0  53 049 ✅  - 9  2 430 💤  - 1  14 ❌ +10 

For more details on these failures, see this check.

Results for commit 65ae7ea. ± Comparison against base commit 92fc0e2.

[phofl]

thx