Try string type.

.gitea/workflows/docker.yaml

@@ -13,19 +13,19 @@ on:
         description: True if the image should be pushed after building
         required: false
         default: false
-        type: boolean
+        type: string # really boolean
 jobs:
   build:
     runs-on: cjyar-24
     steps:
     - name: docker login
-      if: ${{ inputs.push == true }}
+      if: ${{ inputs.push == 'true' }}
       run: docker login -u cjyar -p "${{ secrets.DOCKER_TOKEN }}"
     - uses: actions/checkout@v4
     - name: build
       run: docker build -t ${{ inputs.image_name }}:${{ github.run_number }} .
     - name: push
-      if: ${{ inputs.push == true }}
+      if: ${{ inputs.push == 'true' }}
       run: |
         docker create --name run_${{ github.run_number }} ${{ inputs.image_name }}:${{ github.run_number }}
         docker export -o /tmp/image run_${{ github.run_number }}