Misc tool tweaks (#35734)

Some minor tooling tweaks:

- Ignore .venv in golangci-lint
- Move go tools to tools directory (e.g. everything that is not "build")
- Enable reportUnusedInlineConfigs in eslint, no current violations
- Apply modernize fix in code-batch-process, modernize cli did
apparently not catch it because of the `go:build ignore` tag.

.golangci.yml

@@ -153,6 +153,7 @@ linters:
         text: '(?i)exitAfterDefer:'
     paths:
       - node_modules
+      - .venv
       - public
       - web_src
       - third_party$
@@ -172,6 +173,7 @@ formatters:
     generated: lax
     paths:
       - node_modules
+      - .venv
       - public
       - web_src
       - third_party$