test: pyiceberg-core, pin datafusion and unpin pyarrow (apache#1648)

## Which issue does this PR close?

- Closes #.

## What changes are included in this PR?
Follow up to apache#1635
We dont need to pin pyarrow specifically, just grab it from pyiceberg.
Revert datafusion version threshold to 45. Version 45 is the lowest
version which will still work.
The underlying issue for apache#1635 is with the **newer** versions of
datafusion, mainly datafusion 49 due to a breaking change described in
apache#1647
So pyiceberg-core works with datafusion (python) library 45, 46, 47, and
48. just not 49

I verified locally with all the versions above:
```
hatch env prune && hatch run dev:test
```

i double checked. `insert_into` is available in datafusion 45.
apache/datafusion@7f9a8c0

## Are these changes tested?

Author: kevinjqliu

bindings/python/LICENSE

@@ -0,0 +1 @@
+../../LICENSE

bindings/python/pyproject.toml

@@ -34,6 +34,7 @@ name = "pyiceberg-core"
 readme = "project-description.md"
 requires-python = "~=3.9"
 dynamic = ["version"]
+license = { file = "LICENSE" }
 
 [tool.maturin]
 features = ["pyo3/extension-module"]
@@ -44,7 +45,7 @@ python-source = "python"
 ignore = ["F403", "F405"]
 
 [tool.hatch.envs.dev]
-dependencies = ["maturin>=1.0,<2.0", "pytest>=8.3.2", "pyarrow==16.*", "datafusion==47.*", "pyiceberg[sql-sqlite]>=0.9.1"]
+dependencies = ["maturin>=1.0,<2.0", "pytest>=8.3.2", "datafusion==45.*", "pyiceberg[sql-sqlite,pyarrow]>=0.9.1"]
 
 [tool.hatch.envs.dev.scripts]
 build = "maturin build --out dist --sdist"

bindings/python/tests/test_datafusion_table_provider.py

@@ -27,8 +27,8 @@
 import datafusion
 
 assert (
-    datafusion.__version__ >= "47"
-)  # iceberg table provider only works for datafusion >= 47
+    datafusion.__version__ >= "45"
+)  # iceberg table provider only works for datafusion >= 45
 
 
 @pytest.fixture(scope="session")