Update tree-sitter requirement from 0.19 to 0.20 in /ruby/extractor

Updates the requirements on [tree-sitter](https://github.com/tree-sitter/tree-sitter) to permit the latest version.
- [Release notes](https://github.com/tree-sitter/tree-sitter/releases)
- [Commits](tree-sitter/tree-sitter@v0.19.0...v0.20.6)

---
updated-dependencies:
- dependency-name: tree-sitter
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

ruby/extractor/Cargo.toml

@@ -9,7 +9,7 @@ edition = "2018"
 [dependencies]
 flate2 = "1.0"
 node-types = { path = "../node-types" }
-tree-sitter = "0.19"
+tree-sitter = "0.20"
 tree-sitter-embedded-template = "0.19"
 tree-sitter-ruby = { git = "https://github.com/tree-sitter/tree-sitter-ruby.git", rev = "1ebfdb288842dae5a9233e2509a135949023dd82" }
 clap = "3.0"