evm has incorrect is_static parameter for custom stateful precompiles

SputnikVM, also called evm, is a Rust implementation of Ethereum Virtual Machine. A custom stateful precompile can use the is_static parameter to determine if the call is executed in a static context (via STATICCALL), and thus decide if stateful operations should be done. Prior to version 0.36.0, the passed is_static parameter was incorrect -- it was only set to true if the call came from a direct STATICCALL opcode. However, once a static call context is entered, it should stay static. The issue only impacts custom precompiles that actually uses is_static. For those affected, the issue can lead to possible incorrect state transitions. Version 0.36.0 contains a patch. There are no known workarounds.