Dependencies: Temporarily accept either requirements.txt and requirem…

…ents.dev.txt in the dev container

As part of rucio/rucio#6750, we split
`requirements.txt` in `rucio/rucio` into separate requirements files,
depending on the application. We are keeping this change unreleased
until the next major Rucio release.

Until then, integration tests on `rucio/rucio:master` will use the new
`requirements.dev.txt` file, while the ones on `rucio/rucio:release-34`
will use the old `requirements.txt` file.

This commit is a temporary fix which will be removed after the next
major release. This issue will remain open until then: rucio#323

dev/Dockerfile

@@ -74,7 +74,9 @@ RUN mkdir -p \
 
 RUN python3 -m pip install --no-cache --upgrade pip && \
     python3 -m pip install --no-cache --upgrade setuptools wheel && \
-    if [ -r /tmp/rucio/requirements/requirements.dev.txt ]; then \
+    if [ -r /tmp/rucio/requirements/requirements.txt ]; then \
+        python3 -m pip install --no-cache --upgrade -r /tmp/rucio/requirements/requirements.txt ; \
+    elif [ -r /tmp/rucio/requirements/requirements.dev.txt ]; then \
         python3 -m pip install --no-cache --upgrade -r /tmp/rucio/requirements/requirements.dev.txt ; \
     else \
         python3 -m pip install --no-cache --upgrade -r /tmp/rucio/etc/pip-requires-client \