Update cysignals and cython version requirements

Author: cxzhong

pyproject.toml

@@ -5,7 +5,7 @@ requires = [
   'cypari2 >=2.2.1; sys_platform != "win32"',
   'meson-python',
   # Exclude 1.12.0 because of https://github.com/sagemath/cysignals/issues/212
-  'cysignals >=1.11.2, != 1.12.0',
+  'cysignals >=1.12.1',
   'cython >=3.1.0',
   'gmpy2 >=2.1.5',
   'jinja2',
@@ -45,8 +45,8 @@ dependencies = [
   'cypari2 >=2.2.1; sys_platform != "win32"',
   'six >=1.15.0',
   # Exclude 1.12.0 because of https://github.com/sagemath/cysignals/issues/212
-  'cysignals >=1.11.2, != 1.12.0',
-  'cython >=3.0, != 3.0.3',
+  'cysignals >=1.12.1',
+  'cython >=3.1.0',
   'fpylll >=0.5.9; sys_platform != "win32"',
   'gmpy2 >=2.1.5',
   'ipykernel >=5.2.1',