feat(cargo): support private crate (#24704)

Co-authored-by: Sebastian Poxhofer <secustor@users.noreply.github.com>
Co-authored-by: HonkingGoose <34918129+HonkingGoose@users.noreply.github.com>
Co-authored-by: Rhys Arkins <rhys@arkins.net>

docs/usage/rust.md

@@ -31,9 +31,26 @@ Read the [Rust environment variables docs](https://doc.rust-lang.org/cargo/refer
 
 ## Private crate registries and private Git dependencies
 
-If any dependencies are hosted in private Git repositories, [Git Authentication for cargo](https://doc.rust-lang.org/cargo/appendix/git-authentication.html) must be set up.
-
-If any dependencies are hosted on private crate registries (i.e., not on `crates.io`), then credentials should be set up in such a way that the Git command-line is able to clone the registry index.
-Third-party crate registries usually provide instructions to achieve this.
-
-Both of these are currently only possible when running Renovate self-hosted.
+You as user can set authentication for private crates by adding a `hostRules` configuration to your `renovate.json` file.
+
+All token `hostRules` with a `hostType` (e.g. `github`, `gitlab`, `bitbucket`, etc.) and host rules without a `hostType` will be automatically setup for authentication.
+You can also configure a `hostRules` that's only for Cargo authentication (e.g. `hostType: 'cargo'`).
+
+Here's an example of authentication for a private GitHub and Cargo registry:
+
+```js
+module.exports = {
+  hostRules: [
+    {
+      matchHost: 'github.enterprise.com',
+      token: process.env.GITHUB_TOKEN,
+      hostType: 'github',
+    },
+    {
+      matchHost: 'someGitHost.enterprise.com',
+      token: process.env.CARGO_GIT_TOKEN,
+      hostType: 'cargo',
+    },
+  ],
+};
+```

lib/modules/manager/cargo/__snapshots__/artifacts.spec.ts.snap

@@ -3,7 +3,7 @@
 exports[`modules/manager/cargo/artifacts returns null if unchanged 1`] = `
 [
   {
-    "cmd": "cargo update --manifest-path Cargo.toml --workspace",
+    "cmd": "cargo update --config net.git-fetch-with-cli=true --manifest-path Cargo.toml --workspace",
     "options": {
       "cwd": "/tmp/github/some/repo",
       "encoding": "utf-8",
@@ -26,7 +26,7 @@ exports[`modules/manager/cargo/artifacts returns null if unchanged 1`] = `
 exports[`modules/manager/cargo/artifacts returns updated Cargo.lock 1`] = `
 [
   {
-    "cmd": "cargo update --manifest-path Cargo.toml --workspace",
+    "cmd": "cargo update --config net.git-fetch-with-cli=true --manifest-path Cargo.toml --workspace",
     "options": {
       "cwd": "/tmp/github/some/repo",
       "encoding": "utf-8",
@@ -49,7 +49,7 @@ exports[`modules/manager/cargo/artifacts returns updated Cargo.lock 1`] = `
 exports[`modules/manager/cargo/artifacts returns updated Cargo.lock for lockfile maintenance 1`] = `
 [
   {
-    "cmd": "cargo update --manifest-path Cargo.toml",
+    "cmd": "cargo update --config net.git-fetch-with-cli=true --manifest-path Cargo.toml",
     "options": {
       "cwd": "/tmp/github/some/repo",
       "encoding": "utf-8",
@@ -72,7 +72,7 @@ exports[`modules/manager/cargo/artifacts returns updated Cargo.lock for lockfile
 exports[`modules/manager/cargo/artifacts returns updated workspace Cargo.lock 1`] = `
 [
   {
-    "cmd": "cargo update --manifest-path crates/one/Cargo.toml --workspace",
+    "cmd": "cargo update --config net.git-fetch-with-cli=true --manifest-path crates/one/Cargo.toml --workspace",
     "options": {
       "cwd": "/tmp/github/some/repo",
       "encoding": "utf-8",
@@ -95,7 +95,7 @@ exports[`modules/manager/cargo/artifacts returns updated workspace Cargo.lock 1`
 exports[`modules/manager/cargo/artifacts updates Cargo.lock based on the packageName, when given 1`] = `
 [
   {
-    "cmd": "cargo update --manifest-path Cargo.toml --workspace",
+    "cmd": "cargo update --config net.git-fetch-with-cli=true --manifest-path Cargo.toml --workspace",
     "options": {
       "cwd": "/tmp/github/some/repo",
       "encoding": "utf-8",