v3.78

fix(ci): portable version sync and valid semver; bump actions to Node 24

v3.78 failed for two reasons: macOS BSD sed rejects `sed -i`, and
"3.78" isn't semver (cargo needs major.minor.patch) so all three
builds died on "unexpected end of input while parsing minor version".

- rewrite Cargo.toml via redirect+mv instead of `sed -i`
- normalize the tag to 3-part semver (v3.78 -> 3.78.0, v4 -> 4.0.0)
- actions to their Node 24 majors: checkout v7, setup-java v6,
  setup-go v7, upload-artifact v7, softprops/action-gh-release v3
  (inputs unchanged; clears the Node 20 deprecation warnings)
- Cargo.toml version 3.78.0