Remove 'dbt-core<1.8.9' pin (#1371)

We were facing issues with conflicting dbt core and dbt-databricks when
using the latest release of dbt-core:
```
File "<frozen importlib._bootstrap>", line 1204, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1176, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1147, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line [940](https://github.com/astronomer/astronomer-cosmos/actions/runs/12018236731/job/33502297498?pr=1340#step:7:941), in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/runner/.local/share/hatch/env/virtual/astronomer-cosmos/Za_bFbg4/tests.py3.11-2.6/lib/python3.11/site-packages/dbt/adapters/databricks/__init__.py", line 1, in <module>
    from dbt.adapters.databricks.connections import DatabricksConnectionManager  # noqa
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/.local/share/hatch/env/virtual/astronomer-cosmos/Za_bFbg4/tests.py3.11-2.6/lib/python3.11/site-packages/dbt/adapters/databricks/connections.py", line 27, in <module>
    from dbt.adapters.base import Credentials
ImportError: cannot import name 'Credentials' from 'dbt.adapters.base' (/home/runner/.local/share/hatch/env/virtual/astronomer-cosmos/Za_bFbg4/tests.py3.11-2.6/lib/python3.11/site-packages/dbt/adapters/base/__init__.py)
```

This PR solves this.

Closes: #1343

pyproject.toml

@@ -144,7 +144,7 @@ dependencies = [
     "types-requests",
     "types-python-dateutil",
     "Werkzeug<3.0.0",
-    "dbt-core<1.8.9"  # TODO: https://github.com/astronomer/astronomer-cosmos/issues/1343
+    "dbt-core"
 ]
 pre-install-commands = ["sh scripts/test/pre-install-airflow.sh {matrix:airflow} {matrix:python}"]
 

scripts/test/integration-setup.sh

@@ -6,9 +6,9 @@ set -e
 
 # we install using the following workaround to overcome installation conflicts, such as:
 # apache-airflow 2.3.0 and dbt-core [0.13.0 - 1.5.2] and jinja2>=3.0.0 because these package versions have conflicting dependencies
-pip uninstall -y dbt-postgres dbt-databricks dbt-vertica
+pip uninstall -y 'dbt-bigquery' 'dbt-databricks' 'dbt-postgres' 'dbt-vertica' 'dbt-core'
 rm -rf airflow.*
 pip freeze | grep airflow
 airflow db reset -y
 airflow db init
-pip install 'dbt-core' 'dbt-bigquery' 'dbt-databricks' 'dbt-postgres' 'dbt-vertica' 'openlineage-airflow'
+pip install 'dbt-databricks' 'dbt-bigquery' 'dbt-postgres' 'dbt-vertica' 'openlineage-airflow'