Export checkInvariant from strict-checked-vars

[coot]

• strict-checked-vars: export checkInvariant
• strict-checked-vars-0.1.0.1

[coot]

@lehins there is an unrelated CI failure on Windows:

       NoThunks
        VerKey:                                                                                     OK (8.87s)
          +++ OK, passed 1000 tests.
        SignKey:                                                                                    OK (0.24s)
          +++ OK, passed 1000 tests.
        Cert:                                                                                       Test suite test-crypto: FAIL
Test suite logged to:
D:\a\cardano-base\cardano-base\dist-newstyle\build\x86_64-windows\ghc-9.2.7\cardano-crypto-tests-2.2.0.1\t\test-crypto\test\cardano-crypto-tests-2.2.0.1-test-crypto.log
0 of 1 test suites (0 of 1 test cases) passed.
Error: cabal-3.10.1.0.exe: Tests failed for test:test-crypto from
cardano-crypto-tests-2.2.0.1.

Error: Process completed with exit code 1.

[lehins]

there is an unrelated CI failure on Windows:

@coot I wish I had a way to reproduce it. I've seen Windows test(s) to be a little bit flaky, but I personally don't do Windows, so I opened #430 with hopes someone can pick it up.