build: Update dependencies and build configuration

- Updated `flake.nix` file
- Updated `versionTool` URL to `https://gitlab.schukai.com/oss/utilities/version/-/archive/0.5.0/version-0.5.0.tar.gz`
- Removed commented out `versionTool` hash
- Modified `ldflags` value to include new `gitlab.schukai.com/oss/utilities/documentation-manager` URL
- Removed `vendorSha256` line
- Added `versionTool.defaultPackage.${system}` to `buildInputs` list

flake.nix

@@ -65,7 +65,7 @@
             vendorSha256 = "sha256-81IBG8H1jsYKD+tmFeCpAWFdz6cuQDt9r+FV56xboBU=";
             
             ldflags = [
-                 "-X 'release.version=${version}' -X 'release.build=${build}'"
+                 "-X 'gitlab.schukai.com/oss/utilities/documentation-manager/release.version=${version}' -X 'gitlab.schukai.com/oss/utilities/documentation-manager/release.build=${build}'"
                       ];
                       
             buildInputs = [ versionTool.defaultPackage.${system} ];