chore: Ignore the top level target dir (created by rust-analyzer) (#1628)

Author: eitsupi

.Rbuildignore

@@ -3,6 +3,7 @@
 ^\.vscode$
 ^LICENSE\.md$
 ^\.cache$
+^target$
 ^\.task$
 ^Taskfile\.yml$
 ^\.editorconfig$

.gitignore

@@ -4,7 +4,8 @@
 .task
 
 # cache files
-.cache
+.cache/
+target/
 
 # Generated Makefiles
 src/Makevars