Remove python 3.8 support, add python 3.13 support

[pgoslatara]

Resolves #

Problem

Solution

Checklist

• I have run this code in development, and it appears to resolve the stated issue.
• This PR includes tests, or tests are not required or relevant for this PR.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
src/dbt_bouncer
config_file_validator.py	95	2	98%	138, 144
runner.py	75	4	95%	128, 164–165, 223
utils.py	97	15	85%	38, 43, 137–151, 174
src/dbt_bouncer/artifact_parsers
parsers_common.py	47	1	98%	58
parsers_manifest.py	85	4	95%	173, 175, 183, 258
parsers_run_results.py	33	3	91%	64, 66, 69
src/dbt_bouncer/checks/manifest
check_models.py	199	1	99%	533
check_unit_tests.py	47	3	94%	102, 153, 205
src/dbt_bouncer/checks/run_results
check_run_results.py	19	2	89%	92–93
TOTAL	3994	35	99%

Tests	Skipped	Failures	Errors	Time
1	0 💤	0 ❌	0 🔥	8.337s ⏱️