gnu: Remove rust-better-panic-0.2.

* gnu/packages/crates-io.scm (rust-better-panic-0.2): Delete variable.

gnu: Remove rust-bigdecimal-rs-0.2.

* gnu/packages/crates-io.scm (rust-bigdecimal-rs-0.2): Delete variable.

gnu: Remove rust-block-buffer-0.8.

* gnu/packages/crates-io.scm (rust-block-buffer-0.8): Delete variable.

gnu: Remove rust-boomphf-0.5.

* gnu/packages/crates-io.scm (rust-boomphf-0.5): Delete variable.

gnu: Remove rust-bson-0.14.

* gnu/packages/crates-io.scm (rust-bson-0.14): Delete variable.

gnu: Remove rust-bstr-0.1.

* gnu/packages/crates-io.scm (rust-bstr-0.1): Delete variable.

gnu: Remove rust-bugreport-0.3.

* gnu/packages/crates-io.scm (rust-bugreport-0.3): Delete variable.

gnu: Remove rust-bumpalo-2.

* gnu/packages/crates-io.scm (rust-bumpalo-2): Delete variable.

gnu: Remove rust-cachedir-0.1.

* gnu/packages/crates-io.scm (rust-cachedir-0.1): Delete variable.

gnu: Remove rust-calamine-0.16.

* gnu/packages/crates-io.scm (rust-calamine-0.16): Delete variable.

gnu: Remove rust-capnp-rpc-0.10.

* gnu/packages/crates-io.scm (rust-capnp-rpc-0.10): Delete variable.

gnu: Remove rust-cargo-audit-0.16.

* gnu/packages/crates-io.scm (rust-cargo-audit-0.16): Delete variable.

gnu: Remove rust-cargo-0.51.

* gnu/packages/crates-io.scm (rust-cargo-0.51): Delete variable.

gnu: Remove rust-cfg-expr-0.7.

* gnu/packages/crates-io.scm (rust-cfg-expr-0.7): Delete variable.

gnu: Remove rust-chalk-recursive-0.68.

* gnu/packages/crates-io.scm (rust-chalk-recursive-0.68): Delete variable.

gnu: Remove rust-clipboard-win-2.

* gnu/packages/crates-io.scm (rust-clipboard-win-2): Delete variable.

gnu: Remove rust-colored-1.9.1.

* gnu/packages/crates-io.scm (rust-colored-1.9.1): Delete variable.

gnu: Remove rust-core-text-13.

* gnu/packages/crates-io.scm (rust-core-text-13): Delete variable.

gnu: Remove rust-cov-mark-1.

* gnu/packages/crates-io.scm (rust-cov-mark-1): Delete variable.

gnu: Remove rust-cpuid-bool-0.1.

* gnu/packages/crates-io.scm (rust-cpuid-bool-0.1): Delete variable.