Update sybil requirement from <7,>=6.1.1 to >=6.1.1,<9 (#315)

Updates the requirements on [sybil](https://github.com/simplistix/sybil)
to permit the latest version.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/simplistix/sybil/blob/master/CHANGELOG.rst">sybil's
changelog</a>.</em></p>
<blockquote>
<h2>8.0.0 (20 Sep 2024)</h2>
<ul>
<li>
<p>Drop Python 3.8 support.</p>
</li>
<li>
<p>Internal code tidying.</p>
</li>
</ul>
<p>Thanks to Adam Dangoor for the work on these!</p>
<h2>7.1.1 (16 Sep 2024)</h2>
<ul>
<li>Fix bug that broke docstring collection where a method had an
:any:<code>ellipsis &lt;Ellipsis&gt;</code> in
place of the docstring.</li>
</ul>
<h2>7.1.0 (16 Sep 2024)</h2>
<ul>
<li>
<p>Introduce a <code>pytest</code> extra, such that you can install
Sybil in a way that ensures
compatible versions of Sybil and pytest are used.</p>
</li>
<li>
<p>Fix a :class:<code>DeprecationWarning</code> on Python 3.13.</p>
</li>
</ul>
<p>Thanks to Adam Dangoor for this fix.</p>
<h2>7.0.0 (12 Sep 2024)</h2>
<ul>
<li>
<p>Drop Python 3.7 support.</p>
</li>
<li>
<p>Drop support for pytest versions less than 8.</p>
</li>
<li>
<p>:class:<code>Sybil</code> now takes a name which is used in any test
identifiers it produces.</p>
</li>
<li>
<p>Add support for :rst:dir:<code>code</code> and
:rst:dir:<code>sourcecode</code> directives in both ReST and MyST.</p>
</li>
<li>
<p>Fix bug in the pytest integration that prevented multiple
:class:<code>Sybil</code> instances from
parsing the same file.</p>
</li>
<li>
<p>Fix bug where escaped quotes were not correctly unescaped in regions
extracted from docstrings.</p>
</li>
<li>
<p>Restructure usage documentation, splitting out
:doc:<code>integration</code> and :doc:<code>parsers</code>
documents and introducing a :doc:<code>concepts</code> glossary.</p>
</li>
</ul>
<h2>6.1.1 (9 May 2024)</h2>
<ul>
<li>Fix lexing of indented blocks where embedded blank lines would be
erroneously removed.</li>
</ul>
<p>6.1.0 (22 Apr 2024)</p>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/simplistix/sybil/commit/57717adec2875d73dc5fcdce1dd6500396406685"><code>57717ad</code></a>
Prepare for 8.0.0 release</li>
<li><a
href="https://github.com/simplistix/sybil/commit/822923f6819f4255a56b57c8b6a8a7fa6dcde57c"><code>822923f</code></a>
Move from typing to collections.abc for multiple deprecated imports</li>
<li><a
href="https://github.com/simplistix/sybil/commit/f21cb1bc3bbd556e9f3e9be0e5034eaa82f931be"><code>f21cb1b</code></a>
Merge pull request <a
href="https://redirect.github.com/simplistix/sybil/issues/134">#134</a>
from adamtheturtle/drop-python-3.8</li>
<li><a
href="https://github.com/simplistix/sybil/commit/25f1f6457712922c93df84f8db7aa8e224c15c06"><code>25f1f64</code></a>
Merge pull request <a
href="https://redirect.github.com/simplistix/sybil/issues/136">#136</a>
from adamtheturtle/capture-fixture-moved</li>
<li><a
href="https://github.com/simplistix/sybil/commit/65e2eadc91ec7676c99836e7ddcb423ff4269fa6"><code>65e2ead</code></a>
Move from some _pytest imports to pytest imports</li>
<li><a
href="https://github.com/simplistix/sybil/commit/d5dc627d88f134dbedb941bea041fca2a0131a03"><code>d5dc627</code></a>
Merge pull request <a
href="https://redirect.github.com/simplistix/sybil/issues/135">#135</a>
from adamtheturtle/rm-unused-imports</li>
<li><a
href="https://github.com/simplistix/sybil/commit/b4832c8331f8b7b922ab074ca062f42187492221"><code>b4832c8</code></a>
Remove all unused imports</li>
<li><a
href="https://github.com/simplistix/sybil/commit/198d69e72822e7ccc4e22494dfe1c6f74fe579bb"><code>198d69e</code></a>
Drop support for Python 3.8</li>
<li><a
href="https://github.com/simplistix/sybil/commit/b4c096ac437c85d9031fd1f604a72e24e1a59a49"><code>b4c096a</code></a>
Prepare for 7.1.1 release</li>
<li><a
href="https://github.com/simplistix/sybil/commit/16dfbb0e9ebf5f2b483b0b4da448af42e9972b0b"><code>16dfbb0</code></a>
Exclude Ellipsis from coverage checking</li>
<li>Additional commits viewable in <a
href="https://github.com/simplistix/sybil/compare/6.1.1...8.0.0">compare
view</a></li>
</ul>
</details>
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</details>

Author: llucax

pyproject.toml

@@ -64,7 +64,7 @@ model = []
 extra-lint-examples = [
   "pylint >= 2.17.3, < 4",
   "pytest >= 7.3.0, < 9",
-  "sybil >= 6.1.1, < 7",
+  "sybil >= 6.1.1, < 9",
 ]
 dev-flake8 = [
   "flake8 == 7.1.1",
@@ -107,7 +107,7 @@ dev-pytest = [
   "pylint == 3.3.1",       # We need this to check for the examples
   "cookiecutter == 2.6.0", # For checking the cookiecutter scripts
   "jinja2 == 3.1.4",       # For checking the cookiecutter scripts
-  "sybil >= 6.1.1, < 7",   # Should be consistent with the extra-lint-examples dependency
+  "sybil >= 6.1.1, < 9",   # Should be consistent with the extra-lint-examples dependency
 ]
 dev = [
   "frequenz-repo-config[dev-mkdocs,dev-flake8,dev-formatting,dev-mkdocs,dev-mypy,dev-noxfile,dev-pylint,dev-pytest]",