chore: Update CI for WASI tests to run on more recent nightly build (#1649)

* chore: Update CI for WASI tests to run on more recent nightly build

* Update to latest and update reference in support-tiers.md

* fix: Use nightly with WASI fixes

rust-lang/rust#147572 switched from WASI
specific code in the Rust source to using WASI libc.

The following fixes were required and have been merged into nightly:
* [fix: WASI threading regression by disabling pthread
  usage](rust-lang/rust#151016)
* [Fix std::fs::copy on WASI by setting proper OpenOptions
  flags](rust-lang/rust#150881)

---------

Co-authored-by: Colin Murphy <colmurph@adobe.com>

Author: scouten-adobe

.github/workflows/tier-1a.yml

@@ -442,12 +442,12 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v6
 
-        # nightly required for testing until this issue is resolved:
+        # Nightly required for testing until this issue is resolved:
         # wasip2 target should not conditionally feature gate stdlib APIs rust-lang/rust#130323 https://github.com/rust-lang/rust/issues/130323
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: nightly-2025-08-25
+          toolchain: nightly-2026-01-16
 
       - name: Install wasmtime
         run: |
@@ -460,7 +460,7 @@ jobs:
           sudo apt-get install -y clang
 
       - name: Add wasm32-wasip2 target
-        run: rustup target add --toolchain nightly-2025-08-25 wasm32-wasip2
+        run: rustup target add --toolchain nightly-2026-01-16 wasm32-wasip2
 
       - name: Cache Rust dependencies
         uses: Swatinem/rust-cache@v2
@@ -472,7 +472,7 @@ jobs:
           RUST_MIN_STACK: 16777216
           FEATURES: ${{needs.get-features.outputs.rust-native-features}}
         run: |
-          cargo +nightly-2025-08-25 test --target wasm32-wasip2 -p c2pa --features "$FEATURES" --no-default-features -- --no-capture
+          cargo +nightly-2026-01-16 test --target wasm32-wasip2 -p c2pa --features "$FEATURES" --no-default-features -- --no-capture
 
   clippy_check:
     name: Clippy
@@ -524,11 +524,11 @@ jobs:
       - name: Install nightly toolchain
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: nightly-2025-12-06
+          toolchain: nightly-2026-01-16
           components: rustfmt
 
       - name: Check format
-        run: cargo +nightly-2025-12-06 fmt --all -- --check
+        run: cargo +nightly-2026-01-16 fmt --all -- --check
 
   cargo-deny:
     name: License / vulnerability audit

docs/support-tiers.md

@@ -36,7 +36,7 @@ These requirements are enforced in the [Tier 1A workflow](/.github/workflows/tie
 
 * **Ubuntu:** `x86_64-unknown-linux-gnu`, Rust `stable`, `all` features, `openssl` | `rust_native_crypto`, `glibc`
 * **Wasm:** `wasm32-unknown-unknown`, Rust `stable`, `fetch_remote_manifests` feature, `rust_native_crypto`
-* **WASI:** `wasm32-wasip2`, Rust `nightly-2025-08-25`, `all` features
+* **WASI:** `wasm32-wasip2`, Rust `nightly-2026-01-16`, `all` features
 
 ### Tier 1A for c2pa-c-ffi