Update casaplotms requirement from >=2.7.4 to >=2.8.2

Updates the requirements on [casaplotms](https://open-bitbucket.nrao.edu/projects/CASA/repos/casaplotms/browse) to permit the latest version.

---
updated-dependencies:
- dependency-name: casaplotms
  dependency-version: 2.8.2
  dependency-type: direct:development
...

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Author: dependabot[bot]

pyproject.toml

@@ -47,7 +47,7 @@ dependencies = [
 [project.optional-dependencies]
 casa = [
     "casadata >= 2025.9.22",
-    "casaplotms >= 2.7.4",
+    "casaplotms >= 2.8.2",
     "casarecipes >= 0.4.0",
     "casashell >= 6.7.3.21",
     "casatasks >= 6.7.3.21",