interpreter: Use the same type for SignatureHash in the definition

This was missed during the original PR switching the nHashType argument
to int32_t in SignatureHash in bc52cda.

The problem was discovered after running into a linker error when
attempting to link this code as a static library using the header as a
declaration with a riscv32 bare metal toolchain. The compiler would
error with:

/opt/riscv-ilp32/lib/gcc/riscv32-unknown-elf/13.2.0/../../../../riscv32-unknown-elf/bin/ld: build_kernel_riscv/src/libbitcoin_consensus.a(interpreter.cpp.o): in function `GenericTransactionSignatureChecker<CTransaction>::CheckECDSASignature(std::vector<unsigned char, std::allocator<unsigned char> > const&, std::vector<unsigned char, std::allocator<unsigned char> > const&, CScript const&, SigVersion) const':
/home/user/bitcoin/build_kernel_riscv/./script/interpreter.cpp:2043:(.text._ZNK34GenericTransactionSignatureCheckerI12CTransactionE19CheckECDSASignatureERKSt6vectorIhSaIhEES6_RK7CScript10SigVersion[_ZNK34GenericTransactionSignatureCheckerI12CTransactionE19CheckECDSASignatureERKSt6vectorIhSaIhEES6_RK7CScript10SigVersion]+0xee): undefined reference to `uint256 SignatureHash<CTransaction>(CScript const&, CTransaction const&, unsigned int, int, long long const&, SigVersion, PrecomputedTransactionData const*)'

src/script/interpreter.h

@@ -240,7 +240,7 @@ extern const HashWriter HASHER_TAPLEAF;    //!< Hasher with tag "TapLeaf" pre-fe
 extern const HashWriter HASHER_TAPBRANCH;  //!< Hasher with tag "TapBranch" pre-fed to it.
 
 template <class T>
-uint256 SignatureHash(const CScript& scriptCode, const T& txTo, unsigned int nIn, int nHashType, const CAmount& amount, SigVersion sigversion, const PrecomputedTransactionData* cache = nullptr);
+uint256 SignatureHash(const CScript& scriptCode, const T& txTo, unsigned int nIn, int32_t nHashType, const CAmount& amount, SigVersion sigversion, const PrecomputedTransactionData* cache = nullptr);
 
 class BaseSignatureChecker
 {