[OOB] Upgrades 'flex' to '1.13.0'

[SvcGitHubPATagentoperatorimages]

Automated OOB update requested by SvcGitHubPATagentoperatorimages.

Agent: flex
Version: 1.12.0 -> 1.13.0

[github-actions]

Images built:

dotnet-core: ghcr.io/contrast-security-oss/agent-operator-images/agent-dotnet-core@sha256:8756fbdd2777a3d7afbc5102053231a33acff2b9a2c03d8f946c9eed5b6f3089
dotnet-framework: ghcr.io/contrast-security-oss/agent-operator-images/agent-dotnet-framework@sha256:3cf4876ad9d2081d843144258a8e24fbd3010e54ed1a38b03c1cedd272328633
java: ghcr.io/contrast-security-oss/agent-operator-images/agent-java@sha256:c4b7b20424d6284edeff62941b8bea252bfe19ce300c5a2c89c522183828f3d6
nodejs: ghcr.io/contrast-security-oss/agent-operator-images/agent-nodejs@sha256:207e035e51b1d30cc7c6c5e9019bdd0ce2d875d4fca1cfa536c0e6d58245ecb8
php: ghcr.io/contrast-security-oss/agent-operator-images/agent-php@sha256:60d612b343022036f8524306f174872ccbe25f847743a52143f966bc54faa142
python: ghcr.io/contrast-security-oss/agent-operator-images/agent-python@sha256:a1ecade2dc450e0fe02b21f3e6956ea7a63dbd3ae7eca5e921cd6608694894ad
flex: ghcr.io/contrast-security-oss/agent-operator-images/agent-flex@sha256:13c9613a747bd15219597f35806e191ca7ceca16a2145f8d4453afdc51eb056c