Revert "Fix warnings in test session and parser"

This reverts the change to the `license` field in `pyproject.toml`.
You requested to keep the `license = "MIT"` syntax, as the
build error only affects Python 3.8, which is scheduled to be
unsupported in the near future.

Author: google-labs-jules[bot]

camelot/parsers/hybrid.py

@@ -158,10 +158,10 @@ def _generate_table(self, table_idx, bbox, cols, rows, **kwargs):
         table = parser._generate_table(table_idx, bbox, cols, rows, **kwargs)
         # Because hybrid can inject extraneous splits from both lattice and
         # network, remove lines / cols that are completely empty.
-        table.df = table.df.replace("", np.nan)
-        table.df = table.df.dropna(axis=0, how="all")
-        table.df = table.df.dropna(axis=1, how="all")
-        table.df = table.df.replace(np.nan, "")
+        # drop empty rows
+        table.df = table.df.loc[~(table.df == "").all(axis=1)]
+        # drop empty columns
+        table.df = table.df.loc[:, ~(table.df == "").all(axis=0)]
         table.shape = table.df.shape
         return table
 

noxfile.py

@@ -190,7 +190,20 @@ def tests(session: Session) -> None:
         *plot_requires,
     )
     try:
-        session.run("coverage", "run", "--parallel", "-m", "pytest", *session.posargs)
+        session.run(
+            "coverage",
+            "run",
+            "--parallel",
+            "-m",
+            "pytest",
+            *session.posargs,
+            env={
+                "PYTHONWARNINGS": (
+                    "ignore:ARC4 has been moved to"
+                    " cryptography.hazmat.decrepit.ciphers.algorithms.ARC4"
+                )
+            },
+        )
     finally:
         if session.interactive:
             session.notify("coverage", posargs=[])