feat(tests): EIP-7883: triple modexp gas price (#1881)

* chore(tests): triple modexp gas price.

* chore(tests): update modexp eip-7883 vectors.

* chore(tests): small clarifactions.

Author: spencer-tb

docs/CHANGELOG.md

@@ -121,7 +121,7 @@ Users can select any of the artifacts depending on their testing needs for their
 - 🔀 Refactored `SELFDESTRUCT` opcode collision tests to use the `pre_alloc` plugin in order to avoid contract and EOA address collisions ([#1643](https://github.com/ethereum/execution-spec-tests/pull/1643)).
 - ✨ EIP-7594: Sanity test cases to send blob transactions and verify `engine_getBlobsVX` using the `execute` command ([#1644](https://github.com/ethereum/execution-spec-tests/pull/1644)).
 - 🔀 Refactored EIP-145 static tests into python ([#1683](https://github.com/ethereum/execution-spec-tests/pull/1683)).
-- ✨ EIP-7823, EIP-7883: Add test cases for ModExp precompile gas-cost updates and input limits on Osaka ([#1579](https://github.com/ethereum/execution-spec-tests/pull/1579), [#1729](https://github.com/ethereum/execution-spec-tests/pull/1729)).
+- ✨ EIP-7823, EIP-7883: Add test cases for ModExp precompile gas-cost updates and input limits on Osaka ([#1579](https://github.com/ethereum/execution-spec-tests/pull/1579), [#1729](https://github.com/ethereum/execution-spec-tests/pull/1729), [#1881](https://github.com/ethereum/execution-spec-tests/pull/1881)).
 - ✨ [EIP-7825](https://eips.ethereum.org/EIPS/eip-7825): Add test cases for the transaction gas limit of 2^24 gas ([#1711](https://github.com/ethereum/execution-spec-tests/pull/1711), [#1882](https://github.com/ethereum/execution-spec-tests/pull/1882)).
 - ✨ [EIP-7951](https://eips.ethereum.org/EIPS/eip-7951): add test cases for `P256VERIFY` precompile to support secp256r1 curve [#1670](https://github.com/ethereum/execution-spec-tests/pull/1670).
 - ✨ Introduce blockchain tests for benchmark to cover the scenario of pure ether transfers [#1742](https://github.com/ethereum/execution-spec-tests/pull/1742).

tests/osaka/eip7883_modexp_gas_increase/spec.py

@@ -68,7 +68,7 @@ def calculate_iteration_count(cls, exponent_length: int, exponent: bytes) -> int
     def calculate_gas_cost(
         cls, base_length: int, modulus_length: int, exponent_length: int, exponent: bytes
     ) -> int:
-        """Calculate the ModExp gas cost according to EIP-7883 specification."""
+        """Calculate the ModExp gas cost according to EIP-2565 specification."""
         multiplication_complexity = cls.calculate_multiplication_complexity(
             base_length, modulus_length
         )
@@ -78,13 +78,17 @@ def calculate_gas_cost(
 
 @dataclass(frozen=True)
 class Spec7883(Spec):
-    """Constants and helpers for the ModExp gas cost increase EIP."""
+    """
+    Constants and helpers for the ModExp gas cost increase EIP.
+    These override the original Spec class variables for EIP-7883.
+    """
 
     MODEXP_ADDRESS = 0x05
     MIN_GAS = 500
 
     LARGE_BASE_MODULUS_MULTIPLIER = 2
     EXPONENT_BYTE_MULTIPLIER = 16
+    GAS_DIVISOR = 1  # Overrides the original Spec class GAS_DIVISOR
 
     @classmethod
     def calculate_multiplication_complexity(cls, base_length: int, modulus_length: int) -> int: