Update pyproject.toml in cookiecutter code

black uses information from pyproject.toml. So
update the file with relevant information in
cookiecutter code.

Change-Id: I99c551b735b3fd5f52c9c97a23a4c28fee12868e

ops-sunbeam/shared_code/sunbeam_charm/{{cookiecutter.service_name}}/pyproject.toml

@@ -0,0 +1,39 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+# Testing tools configuration
+[tool.coverage.run]
+branch = true
+
+[tool.coverage.report]
+show_missing = true
+
+[tool.pytest.ini_options]
+minversion = "6.0"
+log_cli_level = "INFO"
+
+# Formatting tools configuration
+[tool.black]
+line-length = 79
+
+[tool.isort]
+profile = "black"
+multi_line_output = 3
+force_grid_wrap = true
+
+# Linting tools configuration
+[tool.flake8]
+max-line-length = 79
+max-doc-length = 99
+max-complexity = 10
+exclude = [".git", "__pycache__", ".tox", "build", "dist", "*.egg_info", "venv"]
+select = ["E", "W", "F", "C", "N", "R", "D", "H"]
+# Ignore W503, E501 because using black creates errors with this
+# Ignore D107 Missing docstring in __init__
+ignore = ["W503", "E501", "D107", "E402"]
+per-file-ignores = []
+docstring-convention = "google"
+# Check for properly formatted copyright header in each file
+copyright-check = "True"
+copyright-author = "Canonical Ltd."
+copyright-regexp = "Copyright\\s\\d{4}([-,]\\d{4})*\\s+%(author)s"