release: target Windows 10 or later

While we will only outwardly support Windows 10+, due to an issue in
mingw-w64, we can't set the *-subsystem-version values higher than to
target Windows 8, so do that as a best effort.

contrib/devtools/symbol-check.py

@@ -260,7 +260,7 @@ def check_PE_libraries(binary) -> bool:
 def check_PE_subsystem_version(binary) -> bool:
     major: int = binary.optional_header.major_subsystem_version
     minor: int = binary.optional_header.minor_subsystem_version
-    if major == 6 and minor == 1:
+    if major == 6 and minor == 2:
         return True
     return False
 

contrib/devtools/test-symbol-check.py

@@ -135,7 +135,7 @@ class TestSymbolChecks(unittest.TestCase):
                 }
         ''')
 
-        self.assertEqual(call_symbol_check(cxx, source, executable, ['-lpdh', '-Wl,--major-subsystem-version', '-Wl,6', '-Wl,--minor-subsystem-version', '-Wl,1']),
+        self.assertEqual(call_symbol_check(cxx, source, executable, ['-lpdh', '-Wl,--major-subsystem-version', '-Wl,6', '-Wl,--minor-subsystem-version', '-Wl,2']),
             (1, 'pdh.dll is not in ALLOWED_LIBRARIES!\n' +
                  executable + ': failed DYNAMIC_LIBRARIES'))
 
@@ -166,7 +166,7 @@ class TestSymbolChecks(unittest.TestCase):
                 }
         ''')
 
-        self.assertEqual(call_symbol_check(cxx, source, executable, ['-lole32', '-Wl,--major-subsystem-version', '-Wl,6', '-Wl,--minor-subsystem-version', '-Wl,1']),
+        self.assertEqual(call_symbol_check(cxx, source, executable, ['-lole32', '-Wl,--major-subsystem-version', '-Wl,6', '-Wl,--minor-subsystem-version', '-Wl,2']),
                 (0, ''))