MAINT: bump required pyproject-metadata version to 0.8.0rc1 -- DO NOT MERGE

Author: dnicolodi

pyproject.toml

@@ -8,7 +8,7 @@ backend-path = ['.']
 requires = [
   'meson >= 0.63.3; python_version < "3.12"',
   'meson >= 1.2.3; python_version >= "3.12"',
-  'pyproject-metadata >= 0.7.1',
+  'pyproject-metadata == 0.8.0rc1',
   'tomli >= 1.0.0; python_version < "3.11"',
 ]
 
@@ -34,7 +34,7 @@ classifiers = [
 dependencies = [
   'meson >= 0.63.3; python_version < "3.12"',
   'meson >= 1.2.3; python_version >= "3.12"',
-  'pyproject-metadata >= 0.7.1',
+  'pyproject-metadata == 0.8.0rc1',
   'tomli >= 1.0.0; python_version < "3.11"',
 ]