### Apache Airflow version

main (development)

### What happened

1. When not providing `project_id` to `BigQueryGetDataOperator` in deferrable mode (`project_id=None`), the query generated by `generate_query` method is bugged, i.e.,: 

````sql
from `None.DATASET.TABLE_ID` limit ...
````

2. `as_dict` param does not work `BigQueryGetDataOperator`.

### What you think should happen instead

1. When `project_id` is `None` - it should be removed from the query along with the trailing dot, i.e.,:

````sql
from `DATASET.TABLE_ID` limit ...
````

2. `as_dict` should be added to the serialization method of `BigQueryGetDataTrigger`.

### How to reproduce

1. Create a DAG file with `BigQueryGetDataOperator` defined as follows:
```python
BigQueryGetDataOperator(
        task_id="bq_get_data_op",
        # project_id="PROJECT_ID",  <-- Not provided
        dataset_id="DATASET",
        table_id="TABLE",
        use_legacy_sql=False,
        deferrable=True
    )
````

2. 1. Create a DAG file with `BigQueryGetDataOperator` defined as follows:
```python
BigQueryGetDataOperator(
        task_id="bq_get_data_op",
        project_id="PROJECT_ID",
        dataset_id="DATASET",
        table_id="TABLE",
        use_legacy_sql=False,
        deferrable=True,
        as_dict=True
    )
````

### Operating System

Debian

### Versions of Apache Airflow Providers

_No response_

### Deployment

Official Apache Airflow Helm Chart

### Deployment details

_No response_

### Anything else

The `generate_query` method is not unit tested (which would have prevented it in the first place) - will be better to add one.

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

BigQueryGetDataTrigger,
    BigQueryInsertJobTrigger,
    BigQueryIntervalCheckTrigger,
    BigQueryTableExistenceTrigger,
    BigQueryTablePartitionExistenceTrigger,
    BigQueryValueCheckTrigger,
)
from airflow.triggers.base import TriggerEvent
from tests.providers.google.cloud.utils.compat import AsyncMock, async_mock
TEST_CONN_ID = "bq_default"
TEST_JOB_ID = "1234"
TEST_GCP_PROJECT_ID = "test-project"
TEST_DATASET_ID = "bq_dataset"
TEST_TABLE_ID = "bq_table"
POLLING_PERIOD_SECONDS = 4.0
TEST_SQL_QUERY = "SELECT count(*) from Any"
TEST_PASS_VALUE = 2
TEST_TOLERANCE = 1
TEST_FIRST_JOB_ID = "5678"
TEST_SECOND_JOB_ID = "6789"
TEST_METRIC_THRESHOLDS: dict[str, int] = {}
TEST_DATE_FILTER_COLUMN = "ds"
TEST_DAYS_BACK = -7
TEST_RATIO_FORMULA = "max_over_min"
TEST_IGNORE_ZERO = True
TEST_GCP_CONN_ID = "TEST_GCP_CONN_ID"
TEST_HOOK_PARAMS: dict[str, Any] = {}
TEST_PARTITION_ID = "1234"
@pytest.fixture
def insert_job_trigger():