When compiling without external signer support, the resulted `bench_bitcoin.exe` fails on Windows:
```
>.\bench_bitcoin.exe -filter=AddrManSelectByNetwork
Error: bad optional access
```

Steps to reproduce the failure:
- cross compiling on Ubuntu 22.04:
```
$ make -j $(nproc) -C depends HOST=x86_64-w64-mingw32 NO_QT=1
$ ./autogen.sh
$ ./configure CONFIG_SITE=$PWD/depends/x86_64-w64-mingw32/share/config.site --disable-external-signer
$ make -j $(nproc)
```
- compiling natively on Windows:

Apply the diff as follows:
```diff
--- a/build_msvc/bitcoin_config.h.in
+++ b/build_msvc/bitcoin_config.h.in
@@ -41,9 +41,6 @@
 /* Define this symbol to enable ZMQ functions */
 #define ENABLE_ZMQ 1
 
-/* define if external signer support is enabled (requires Boost::Process) */
-#define ENABLE_EXTERNAL_SIGNER /**/
-
 /* Define to 1 if you have the declaration of `be16toh', and to 0 if you
    don't. */
 #define HAVE_DECL_BE16TOH 0
```
Then
```
>py -3 build_msvc\msvc-autogen.py
>msbuild build_msvc\bitcoin.sln -property:Configuration=Release -verbosity:minimal
>src\bench_bitcoin.exe -filter=AddrManSelectByNetwork
Error: bad optional access
```

---

The failure does not manifest itself when running `bench_bitcoin.exe` using Wine on Linux.
{
    std::vector<unsigned char> result;
    std::vector<unsigned char> expected(ParseHex_expected, ParseHex_expected + sizeof(ParseHex_expected));
    
    result = ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f");
    BOOST_CHECK_EQUAL_COLLECTIONS(result.begin(), result.end(), expected.begin(), expected.end());
    result = TryParseHex<uint8_t>("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f").value();
    BOOST_CHECK_EQUAL_COLLECTIONS(result.begin(), result.end(), expected.begin(), expected.end());
    
    result = ParseHex("12 34 56 78");
    BOOST_CHECK(result.size() == 4 && result[0] == 0x12 && result[1] == 0x34 && result[2] == 0x56 && result[3] == 0x78);
    result = TryParseHex<uint8_t>("12 34 56 78").value();
    BOOST_CHECK(result.size() == 4 && result[0] == 0x12 && result[1] == 0x34 && result[2] == 0x56 && result[3] == 0x78);
    
    result = ParseHex(" 89 34 56 78");
    BOOST_CHECK(result.size() == 4 && result[0] == 0x89 && result[1] == 0x34 && result[2] == 0x56 && result[3] == 0x78);