Disable nightly rust checks for bors (#3427)

This is a temporary measure while we wait for rust-lang/rust#92163 to be resolved.

Author: cart

.github/bors.toml

@@ -2,16 +2,16 @@ status = [
     "build (stable, windows-latest)",
     "build (stable, ubuntu-latest)",
     "build (stable, macos-latest)",
-    "build (nightly, ubuntu-latest)",
+    # "build (nightly, ubuntu-latest)",
     "build-wasm (stable, ubuntu-latest)",
-    "build-wasm (nightly, ubuntu-latest)",
+    # "build-wasm (nightly, ubuntu-latest)",
     "build-android",
     "markdownlint",
     "check-markdown-links",
     "run-examples",
     "check-doc",
     "check-missing-examples-in-docs",
-    "check-unused-dependencies",
+    # "check-unused-dependencies",
     "ci",
     "check-benches",
 ]