ci: fix saving build artifacts for osx and freebsd

When `${{ matrix.tarantool-branch}}` is `release/3.0` or similar, the
step to save build artifacts will fail with the following error:

    Error: Artifact name is not valid: osx-13-x86_64-release/3.0-debug.
    Contains the following character:  Forward slash /

This commit fixes the issue.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

.github/workflows/freebsd.yml

@@ -47,11 +47,20 @@ jobs:
         with:
           bot-token: ${{ secrets.VKTEAMS_BOT_TOKEN }}
 
+      - name: Calculate short name for Tarantool branch
+        if: failure()
+        run: >
+          echo "SHORT_BRANCH_NAME=$(basename ${{ matrix.tarantool-branch }})" >>
+          $GITHUB_ENV
+
       - name: Upload artifacts
         uses: actions/upload-artifact@v3
         if: failure()
         with:
-          name: freebsd-${{ matrix.freebsd-version }}-${{ matrix.tarantool-branch }}
+          name: ${{ format(
+            'freebsd-{0}-{1}',
+            matrix.freebsd-version,
+            env.SHORT_BRANCH_NAME) }}
           retention-days: 21
           path: ${{ env.VARDIR }}/artifacts
 

.github/workflows/osx.yml

@@ -77,6 +77,12 @@ jobs:
         with:
           bot-token: ${{ secrets.VKTEAMS_BOT_TOKEN }}
 
+      - name: Calculate short name for Tarantool branch
+        if: failure()
+        run: >
+          echo "SHORT_BRANCH_NAME=$(basename ${{ matrix.tarantool-branch }})" >>
+          $GITHUB_ENV
+
       - name: Upload artifacts
         uses: actions/upload-artifact@v3
         if: failure()
@@ -85,7 +91,7 @@ jobs:
             'osx-{0}-{1}-{2}-{3}',
             matrix.osx-version,
             matrix.machine-arch,
-            matrix.tarantool-branch,
+            env.SHORT_BRANCH_NAME,
             matrix.build-type) }}
           retention-days: 21
           path: ${{ env.VARDIR }}/artifacts