chore(deps): Update cft/developer-tools Docker tag to v1.19 (#178)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

build/int.cloudbuild.yaml

@@ -41,4 +41,4 @@ tags:
 - 'integration'
 substitutions:
   _DOCKER_IMAGE_DEVELOPER_TOOLS: 'cft/developer-tools'
-  _DOCKER_TAG_VERSION_DEVELOPER_TOOLS: '1.18'
+  _DOCKER_TAG_VERSION_DEVELOPER_TOOLS: '1.19'

build/lint.cloudbuild.yaml

@@ -21,4 +21,4 @@ tags:
 - 'lint'
 substitutions:
   _DOCKER_IMAGE_DEVELOPER_TOOLS: 'cft/developer-tools'
-  _DOCKER_TAG_VERSION_DEVELOPER_TOOLS: '1.18'
+  _DOCKER_TAG_VERSION_DEVELOPER_TOOLS: '1.19'