fix(ci): read Node version from .nvmrc in impact/visual workflows (#8431)

These jobs already check out the repo, so hardcoding 22.23.1 drifts from
.nvmrc unlike every other setup-node workflow (#8393).

Co-authored-by: marktech0813 <marktech0813@users.noreply.github.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: loopover-orb[bot] <296761690+loopover-orb[bot]@users.noreply.github.com>

Author: 3 people

.github/workflows/gittensor-impact.yml

@@ -36,7 +36,7 @@ jobs:
       - name: Setup Node
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
-          node-version: 22.23.1
+          node-version-file: .nvmrc
 
       - name: Render impact card
         run: node --experimental-strip-types scripts/gittensor-impact-card.ts JSONbored/loopover gittensor-impact-dark.svg

.github/workflows/visual-capture-fallback.yml

@@ -98,7 +98,7 @@ jobs:
       - name: Setup Node
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
-          node-version: "22.23.1"
+          node-version-file: .nvmrc
 
       - name: Build
         env: