ci: install and run the reference on Node.js 26

The ts-oracle runs on Node.js 26; the reference's install and the
parity lanes move to it too, so the CLI is compared with the reference
on one Node.js. node-pty 1.0.0, the reference's, builds and spawns a
pty on Node.js 26.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: aledbf

.github/actions/setup-parity-runtime/action.yml

@@ -17,7 +17,7 @@ runs:
         version: 11.27.1
     - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
       with:
-        node-version: "24"
+        node-version: "26"
     # Free disk, enable the containerd image store (build-cache export) and turn
     # bake's filesystem entitlement off. Reuses the Taskfile so the runner prep
     # is identical to release.yml.

.github/workflows/go-cli.yml

@@ -134,7 +134,7 @@ jobs:
           version: 11.27.1
       - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7
         with:
-          node-version: "24"
+          node-version: "26"
 
       - run: go tool task reference
       - run: go tool task parity:contract

.github/workflows/release.yml

@@ -64,7 +64,7 @@ jobs:
           version: 11.27.1
       - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7
         with:
-          node-version: "24"
+          node-version: "26"
 
       - run: go tool task lint
       - run: go tool task spec:compliance
@@ -99,7 +99,7 @@ jobs:
           version: 11.27.1
       - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7
         with:
-          node-version: "24"
+          node-version: "26"
       # parity:runtime exports build cache (build.cache-to-*, build.output-oci-*),
       # which the default docker driver cannot do — its precondition fails ~1s in.
       # Reuse the same runner prep as the go-cli.yml runtime job, or a tagged
@@ -240,7 +240,7 @@ jobs:
           version: 11.27.1
       - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7
         with:
-          node-version: "24"
+          node-version: "26"
 
       - run: go tool task build:cross
       - run: go tool task reference