Proposed changes to create release v0.7.0-rc.4 of libCellML

[github-actions]

Automated release PR for v0.7.0-rc.4.

Do not merge this PR, it is only for review and testing.
The release process will deal with it when the release is finalised.

[github-actions]

Unit Tests

✅ CI checks passed successfully.

[github-actions]

Documentation Tests

✅ Documentation checks passed successfully.

{
  "end_to_end_test_repo": "libcellml/end-to-end-test-framework",
  "end_to_end_test_tag": "v0.5.0",
  "end_to_end_test_sha": "78ce433c2cd4081f123fc2e7fe7d89fcaaf351ae",
  "database_repo": "libcellml/libcellml.org-documentation-test-database",
  "database_tag": "v0.4.1",
  "database_sha": "714d3b125d8f6f3f5e0216e105e095ca6a30e7d8",
  "timestamp": "2026-06-22T06:23:27Z",
  "test_summary": {
    "total_failed": 0,
    "libcellml_asides": {
      "passed": 6,
      "failed": 0
    },
    "libcellml_howto": {
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      "failed": 0
    },
    "libcellml_runtimecodes": {
      "passed": 1,
      "failed": 0
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    "libcellml_tutorials": {
      "passed": 20,
      "failed": 0
    }
  }
}