Docs long build fix (openvinotoolkit#24406)

### Details:
 - *item1*
 - *...*

### Tickets:
 - *ticket-id*

.github/workflows/build_doc.yml

@@ -50,7 +50,7 @@ jobs:
       - name: Build docs
         run: |
           rm -rf build && mkdir build && cd build
-          cmake .. -DCMAKE_BUILD_TYPE=Release -DENABLE_DOCS=ON -DENABLE_CPP_API=ON
+          cmake .. -DCMAKE_BUILD_TYPE=Release -DENABLE_DOCS=ON
           cmake --build . --target sphinx_docs
 
       - name: Cache documentation
@@ -68,12 +68,6 @@ jobs:
           PR_NUMBER=$(echo $GITHUB_REF | awk 'BEGIN { FS = "/" } ; { print $3 }')
           echo "PR_NUMBER=$PR_NUMBER" >> $GITHUB_ENV
 
-      - name: 'Upload doxygen.log'
-        uses: actions/upload-artifact@v4
-        with:
-          name: doxygen_build_log_${{ env.PR_NUMBER }}.log
-          path: build/docs/doxygen.log
-
       - name: 'Upload sphinx.log'
         uses: actions/upload-artifact@v4
         with:
@@ -88,12 +82,10 @@ jobs:
 
       - name: Run Pytest
         run: |
-          pytest --doxygen="./build/docs/doxygen.log" \
-                 --sphinx="./build/docs/sphinx.log" \
+          pytest --sphinx="./build/docs/sphinx.log" \
                  --suppress-warnings="./docs/scripts/tests/suppress_warnings.txt" \
                  --confcutdir="./docs/scripts/tests/" \
                  --html="./build/docs/_artifacts/doc-generation.html" \
-                 --doxygen-strip="$(pwd)" \
                  --sphinx-strip="$(pwd)/build/docs/sphinx_source" \
                  --xfail="./docs/scripts/tests/xfail.txt" \
                  --self-contained-html ./docs/scripts/tests/test_docs.py

docs/requirements.txt

@@ -47,5 +47,4 @@ sphinxcontrib-serializinghtml==1.1.9
 toml==0.10.2
 urllib3==1.26.18
 zipp==3.4.1
-openvino
 docs/openvino_custom_sphinx_sitemap

docs/sphinx_setup/conf.py

@@ -34,6 +34,11 @@
     'breathe'
     ]
 
+try:
+    import openvino
+except ImportError:
+    autodoc_mock_imports = ["openvino"]
+
 breathe_projects = {
     "openvino": "../xml/"
 }