chore: re-enable e2e tests, fixups anthropic API tools support (#8296)

* chore(tests): add mock backend e2e tests

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* Fixup anthropic tests

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* prepare e2e tests

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* Drop repetitive tests

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* Drop specific CI workflow

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* fixup anthropic issues, move all e2e tests to use mocked backend

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

---------

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

.github/workflows/tests-e2e.yml

@@ -0,0 +1,56 @@
+---
+name: 'E2E Backend Tests'
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+    tags:
+      - '*'
+
+concurrency:
+  group: ci-tests-e2e-backend-${{ github.head_ref || github.ref }}-${{ github.repository }}
+  cancel-in-progress: true
+
+jobs:
+  tests-e2e-backend:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: ['1.25.x']
+    steps:
+      - name: Clone
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+      - name: Setup Go ${{ matrix.go-version }}
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go-version }}
+          cache: false
+      - name: Display Go version
+        run: go version
+      - name: Proto Dependencies
+        run: |
+          # Install protoc
+          curl -L -s https://github.com/protocolbuffers/protobuf/releases/download/v26.1/protoc-26.1-linux-x86_64.zip -o protoc.zip && \
+          unzip -j -d /usr/local/bin protoc.zip bin/protoc && \
+          rm protoc.zip
+          go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.34.2
+          go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@1958fcbe2ca8bd93af633f11e97d44e567e945af
+          PATH="$PATH:$HOME/go/bin" make protogen-go
+      - name: Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential
+      - name: Test Backend E2E
+        run: |
+          PATH="$PATH:$HOME/go/bin" make build-mock-backend test-e2e
+      - name: Setup tmate session if tests fail
+        if: ${{ failure() }}
+        uses: mxschmitt/action-tmate@v3.23
+        with:
+          detached: true
+          connect-timeout-seconds: 180
+          limit-access-to-actor: true