Bump coverage[toml] from 7.7.1 to 7.8.0 in /travertino (beeware#3332)

Bumps [coverage[toml]](https://github.com/nedbat/coveragepy) from 7.7.1 to 7.8.0.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](coveragepy/coveragepy@7.7.1...7.8.0)

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

changes/3332.misc.rst

@@ -0,0 +1 @@
+Updated coverage[toml] from 7.7.1 to 7.8.0 in /travertino.

travertino/pyproject.toml

@@ -45,7 +45,7 @@ classifiers = [
 [project.optional-dependencies]
 # These are needed in order to run Travertino's test suite.
 dev = [
-    "coverage[toml] == 7.7.1",
+    "coverage[toml] == 7.8.0",
     "coverage-conditional-plugin == 0.9.0",
     "pytest == 8.3.5",
     "tox == 4.25.0",