fix(aerospike extension): turn off build in Travis due to image version

PHP 8.0 is not supported by Aerospike. See the issue's references.

Closes #2881

workspace/Dockerfile

@@ -872,18 +872,22 @@ RUN set -xe; \
     && \
       if [ $(php -r "echo PHP_MAJOR_VERSION;") = "5" ]; then \
         ( \
-            cd /tmp/aerospike-client-php/src/aerospike \
-            && phpize \
-            && ./build.sh \
-            && make install \
+          cd /tmp/aerospike-client-php/src/aerospike \
+          && phpize \
+          && ./build.sh \
+          && make install \
         ) \
       else \
-        ( \
-            cd /tmp/aerospike-client-php/src \
-            && phpize \
-            && ./build.sh \
-            && make install \
-        ) \
+        if [ $(php -r "echo PHP_MAJOR_VERSION;") = "7" ]; then \
+          ( \
+              cd /tmp/aerospike-client-php/src \
+              && phpize \
+              && ./build.sh \
+              && make install \
+          ) \
+        else \
+          echo "AEROSPIKE does not support PHP 8.0"
+        fi \
       fi \
     && rm /tmp/aerospike-client-php.tar.gz \
     && echo 'extension=aerospike.so' >> /etc/php/${LARADOCK_PHP_VERSION}/cli/conf.d/aerospike.ini \