#97)

The optional `hyperdb-compile-check = "=0.3.1"` dependency in
hyperdb-api-derive/Cargo.toml was the only internal exact-version pin in
the workspace NOT wrapped in `# x-release-please-start-version` /
`# x-release-please-end` markers. release-please therefore bumped
hyperdb-compile-check's own version (and every other internal pin) to the
new release version but left this consumer pin at =0.3.1, making the
workspace unresolvable:

    error: failed to select a version for the requirement
    `hyperdb-compile-check = "=0.3.1"`
    candidate versions found which didn't match: 0.4.0
    required by package `hyperdb-api-derive`

This broke the v0.4.0 release-please PR (#95): clippy, all three test
matrices, cargo-deny, publish-dry-run, and node-bindings all failed on
dependency resolution. Wrapping the pin lets release-please bump it in
lockstep with the rest of the workspace, as it already does for the
hyperdb-api dev-dependency pin a few lines below.