astroid: unpin the builder image and bump the pip version (#13416)

Author: correctmost

projects/astroid/Dockerfile

@@ -14,12 +14,9 @@
 #
 ##########################################################################
 
-# Held back because of github.com/google/oss-fuzz/pull/13407
-# Please fix the build failure + upgrade.
+FROM gcr.io/oss-fuzz-base/base-builder-python
 
-FROM gcr.io/oss-fuzz-base/base-builder-python@sha256:d223a882810372830fd7968eb3e64533f3a2318c90be43ac753a46a15946faec
-
-RUN pip3 install --disable-pip-version-check --no-cache-dir pip==24.2
+RUN pip3 install --disable-pip-version-check --no-cache-dir pip==25.1.1
 
 RUN git clone --depth=1 --no-tags https://github.com/pylint-dev/astroid