Try to fix publishing

This errro specifically:

Updating crates.io index
	 error: failed to select a version for the requirement `ra_ap_stdx = "^0.0.0"`
	 candidate versions found which didn't match: 0.0.20
	 location searched: /home/runner/work/rust-analyzer/rust-analyzer/crates/stdx
	 required by package `ra_ap_completion v0.0.20 (/home/runner/work/rust-analyzer/rust-analyzer/crates/completion)`
	 error: unable to update Cargo.lock
	 Error: Process completed with exit code 1.

Author: matklad

crates/completion/Cargo.toml

@@ -14,6 +14,7 @@ itertools = "0.9.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 
+stdx = { path = "../stdx", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 text_edit = { path = "../text_edit", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
@@ -29,4 +30,3 @@ hir = { path = "../hir", version = "0.0.0" }
 
 [dev-dependencies]
 expect-test = "1.0"
-stdx = { path = "../stdx", version = "0.0.0" }