Cleanup - mock InvokeContext (#31007)

* Turns with_mock_invoke_context() into a macro.

* Removes prepare_mock_invoke_context().

* Replaces InvokeContext::new_mock() with with_mock_invoke_context().

* Removes InvokeContext::new_mock().

* Removes Cow from InvokeContext::sysvar_cache.

* Removes override parameters from mock_process_instruction().

* cargo fmt

cli/src/program.rs

@@ -37,6 +37,7 @@ use {
         account_utils::StateMut,
         bpf_loader, bpf_loader_deprecated,
         bpf_loader_upgradeable::{self, UpgradeableLoaderState},
+        feature_set::FeatureSet,
         instruction::{Instruction, InstructionError},
         loader_instruction,
         message::Message,
@@ -46,9 +47,7 @@ use {
         signature::{keypair_from_seed, read_keypair_file, Keypair, Signature, Signer},
         system_instruction::{self, SystemError},
         system_program,
-        sysvar::rent::Rent,
         transaction::{Transaction, TransactionError},
-        transaction_context::TransactionContext,
     },
     std::{
         fs::File,
@@ -2018,12 +2017,10 @@ fn read_and_verify_elf(program_location: &str) -> Result<Vec<u8>, Box<dyn std::e
     let mut program_data = Vec::new();
     file.read_to_end(&mut program_data)
         .map_err(|err| format!("Unable to read program file: {err}"))?;
-    let mut transaction_context = TransactionContext::new(Vec::new(), Some(Rent::default()), 1, 1);
-    let invoke_context = InvokeContext::new_mock(&mut transaction_context, &[]);
 
     // Verify the program
     let loader = create_loader(
-        &invoke_context.feature_set,
+        &FeatureSet::default(),
         &ComputeBudget::default(),
         true,
         true,