Update Rust nightly toolchain every ~6 weeks

Follow the stable release cycle.

[no ci]

renovate.json

@@ -9,8 +9,8 @@
   "customManagers": [
     {
       "customType": "regex",
-      "fileMatch": [
-        "(^|/)CMakeLists\\.txt$"
+      "managerFilePatterns": [
+        "/(^|/)CMakeLists\\.txt$/"
       ],
       "matchStrings": [
         "(?<depName>\\S*)\\s*GIT_REPOSITORY https://(?<datasource>.*?)\\.com/(?<packageName>.*?)\\.git\\s*GIT_TAG (?<currentValue>\\S*)"
@@ -19,8 +19,8 @@
     },
     {
       "customType": "regex",
-      "fileMatch": [
-        "^chrome.version$"
+      "managerFilePatterns": [
+        "chrome.version"
       ],
       "matchStrings": [
         "(?<currentValue>\\S+)"
@@ -28,12 +28,28 @@
       "depNameTemplate": "chrome",
       "datasourceTemplate": "custom.chrome",
       "extractVersionTemplate": "^(?<version>\\d+)"
+    },
+    {
+      "customType": "regex",
+      "managerFilePatterns": [
+        "rust-toolchain.toml"
+      ],
+      "matchStrings": [
+        "channel = \"nightly-(?<currentValue>[^\"]+)\""
+      ],
+      "versioningTemplate": "regex:^(?<major>\\d{4})-(?<minor>\\d{2})-(?<patch>\\d{2})$",
+      "datasourceTemplate": "custom.rust-nightly",
+      "depNameTemplate": "rust-nightly"
     }
   ],
   "customDatasources": {
     "chrome": {
       "defaultRegistryUrlTemplate": "https://googlechromelabs.github.io/chrome-for-testing/LATEST_RELEASE_STABLE",
       "format": "plain"
+    },
+    "rust-nightly": {
+      "defaultRegistryUrlTemplate": "https://rust-lang.github.io/rustup-components-history/aarch64-linux-android/rust-std",
+      "format": "plain"
     }
   },
   "packageRules": [
@@ -64,6 +80,15 @@
         "nettle"
       ],
       "versioning": "regex:^nettle_(?<major>\\d+)\\.(?<minor>\\d+)(?:\\.(?<patch>\\d+))?(?<prerelease>rc\\d+)?"
+    },
+    {
+      "matchDepNames": [
+        "rust-nightly"
+      ],
+      "schedule": [
+        "* * 1 */3 *",
+        "* * 15 2-11/3 *"
+      ]
     }
   ],
   "lockFileMaintenance": {