chore(deps): Update Rust Stable to v1.91

Author: renovate[bot]

.github/workflows/ci.yml

@@ -111,7 +111,7 @@ jobs:
     - name: Install Rust
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: "1.90"  # STABLE
+        toolchain: "1.91"  # STABLE
     - uses: Swatinem/rust-cache@v2
     - name: Check documentation
       env:
@@ -126,7 +126,7 @@ jobs:
     - name: Install Rust
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: "1.90"  # STABLE
+        toolchain: "1.91"  # STABLE
         components: rustfmt
     - uses: Swatinem/rust-cache@v2
     - name: Check formatting
@@ -142,7 +142,7 @@ jobs:
     - name: Install Rust
       uses: dtolnay/rust-toolchain@stable
       with:
-        toolchain: "1.90"  # STABLE
+        toolchain: "1.91"  # STABLE
         components: clippy
     - uses: Swatinem/rust-cache@v2
     - name: Install SARIF tools