Pin CI Rust toolchain to 1.97.1

Rust 1.98.0 (released 2026-08-20) passes --fix-cortex-a53-843419 to the
linker for aarch64-unknown-linux-musl, which the zig cc wrapper used by
cargo-zigbuild rejects, breaking the release build for that target. Pin
all workflows that installed unpinned stable to 1.97.1 until the zig
toolchain handles the new flag. The nightly-2026-04-14 fmt/clippy
toolchains are unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/nightly.yml

@@ -54,6 +54,8 @@ jobs:
       - name: Set up Rust
         if: steps.skip.outputs.skip != 'true'
         uses: dtolnay/rust-toolchain@631a55b12751854ce901bb631d5902ceb48146f7 # stable
+        with:
+          toolchain: 1.97.1
 
       - uses: taiki-e/install-action@773334c0e05d7e699e4d78234494308223f3a2cf # nextest
         if: steps.skip.outputs.skip != 'true'

.github/workflows/release.yml

@@ -67,6 +67,7 @@ jobs:
       - name: Set up Rust
         uses: dtolnay/rust-toolchain@631a55b12751854ce901bb631d5902ceb48146f7 # stable
         with:
+          toolchain: 1.97.1
           targets: ${{ matrix.target }}
 
       - name: Set up zig

.github/workflows/rust.yml

@@ -101,6 +101,8 @@ jobs:
         with:
           persist-credentials: false
       - uses: dtolnay/rust-toolchain@631a55b12751854ce901bb631d5902ceb48146f7 # stable
+        with:
+          toolchain: 1.97.1
       - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2
         with:
           cache-on-failure: true
@@ -116,6 +118,8 @@ jobs:
         with:
           persist-credentials: false
       - uses: dtolnay/rust-toolchain@631a55b12751854ce901bb631d5902ceb48146f7 # stable
+        with:
+          toolchain: 1.97.1
       - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2
         with:
           cache-on-failure: true
@@ -140,6 +144,8 @@ jobs:
         with:
           persist-credentials: false
       - uses: dtolnay/rust-toolchain@631a55b12751854ce901bb631d5902ceb48146f7 # stable
+        with:
+          toolchain: 1.97.1
       - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2
         with:
           cache-on-failure: true

.github/workflows/typescript.yml

@@ -73,5 +73,7 @@ jobs:
       - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2.2.0
       - run: bun install --frozen-lockfile
       - uses: dtolnay/rust-toolchain@631a55b12751854ce901bb631d5902ceb48146f7 # stable
+        with:
+          toolchain: 1.97.1
       - run: cargo --locked dev build -- --locked -p fabro-cli --release
       - run: wc -c < target/release/fabro