feat(terra/contributing): remove outdated go macros

Author: madonuko

pages/terra/contributing.mdx

@@ -193,8 +193,6 @@ For other macros available in Fedora/Terra, check out our unofficial [macros lis
 | `%cargo_prep_online`            | Enables internet access for `cargo`. Replaces `%cargo_prep` in `%prep` |
 | `%cargo_license_online`         | Replaces `%cargo_license` in `%build`                                  |
 | `%cargo_license_summary_online` | Replaces `%cargo_license_summary` in `%build`                          |
-| `%go_prep_online`               | Same as `go mod download`                                              |
-| `%go_build_online %goipath`     | Builds a go package in `%build`                                        |
 | `%nim_prep`                     | Setting up `nimble`                                                    |
 | `%nim_build` or `%nim_c`        | Builds a package. Requires an argument to `src/pkgname`                |