Change integ test to use assumerole

[RanVaknin]

Changing the integ test buildspec to assume a cross account role to provision resources and run integ tests.
The new buildspec writes assume role into an INI config file in memory, which then the SDK integ test clients use to automatically refresh credentials.

Some tests are disabled because the specific service / operation they test is no longer supported on new accounts (essentially EOL).

• Disabled selectObjectContent tests - this failed with a 405 despite having the right permissions. The only explanation I was able to find is this RE:post response mentioning access to select was cut off for newer accounts.
• Disabled DataPipeline tests - access to this service was cut off. Blogpost

[RanVaknin]

Question:
currently I have some tests disabled because end of support for new accounts. In theory customers might still be using them. Do we need to run these separately from an older account? Or the exact opposite is true, instead of disabling them should I remove them completely?

[dagnir]

Not a blocker but let's add a TODO + backlog item to move these to wiremock tests.

[sonarqubecloud]

Quality Gate failed

Failed conditions
34.8% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud