fix(errors): create cache dir before writing lock file

.omo/evidence/task-26-tofu-core.log

@@ -152,3 +152,32 @@ install failed: conflict detectedtestpkg-2.1 is already installed -- use -ReProv
   Up-to-date toml 1.0.0: target for configuration [library] is up to date.
   Up-to-date tofu ~main: target for configuration [application] is up to date.
     Finished To force a rebuild of up-to-date targets, run again with --force
+ ok  build plan: 1 packages
+==> generating build plan
+  -    + libfoo (recipe)
+  -    + mypkg (recipe)
+ ok  build plan: 2 packages
+23 modules passed unittests
+=== Re-verification after crash fix ===
+--- rm -rf ~/.cache/tofu && ./tofu --help ---
+tofu — ZUUR package manager
+Usage: tofu <command> [arg] [flags]
+Commands:
+  -S <pkg>     Install package from ZUUR recipes
+  -Ss <q>      Search ZUUR
+  -Syu         Upgrade installed packages
+  -R <pkg>     Remove package
+  -Si <pkg>    Show package info
+  -h, --help   Show this help
+Flags:
+  --noconfirm  Skip confirmation prompts
+  --dry-run    Show what would happen without doing it
+  --force      Overwrite existing builds
+  -j<N>        Parallel build jobs
+
+EXIT: 0
+--- ./tofu (no args) ---
+error no command given (run 'tofu --help')
+EXIT: 0
+--- dub test result ---
+23 modules passed unittests