Update dependency rust to nightly-2026-06-25

Author: renovate[bot]

.github/workflows/nightly.yml

@@ -132,7 +132,7 @@ jobs:
             - name: Set up Rust (nightly)
               uses: dtolnay/rust-toolchain@stable
               with:
-                  toolchain: nightly-2025-07-04
+                  toolchain: nightly-2026-06-25
 
             - name: Install Rust target
               run: rustup target add ${{ matrix.target }}

.github/workflows/release.yml

@@ -141,7 +141,7 @@ jobs:
       - name: Set up Rust (nightly)
         uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: nightly-2025-07-04
+          toolchain: nightly-2026-06-25
 
       - name: Install Rust target
         run: rustup target add ${{ matrix.target }}