[MNT] Set upper bound on esig version (#2463)

Bounded esig to <1.0.0 to avoid breaking CI for python 3.9

pyproject.toml

@@ -58,9 +58,11 @@ dependencies = [
 [project.optional-dependencies]
 # soft dependencies
 all_extras = [
-    "esig>=0.9.7; platform_system != 'Darwin' and python_version < '3.11'",
+    # Upper bound set as <1.0.0 as 1.0 dropped support for python 3.9. We will remove
+    # the upper bound once we also drop support for python 3.9 later in 2025.
+    "esig>=0.9.7,<1.0.0; platform_system != 'Darwin' and python_version < '3.11'",
     "imbalanced-learn",
-    "matplotlib>=3.3.2",
+    "matplotlib>=3.3.2",  # Remove upper bound
     "pycatch22>=0.4.5",
     "pyod>=1.1.3",
     "prts>=1.0.0.0",