[OOB] Upgrades 'flex' to '3.1.0'

[SvcGitHubPATagentoperatorimages]

Automated OOB update requested by SvcGitHubPATagentoperatorimages.

Agent: flex
Version: 3.0.3 -> 3.1.0

[github-actions]

Images built:

dotnet: ghcr.io/contrast-security-oss/agent-operator-images/agent-dotnet@sha256:0fd066b8a250a52422b1857daff9fa0c0044262984c44553188dd0f0325c76d7
dotnet-core: ghcr.io/contrast-security-oss/agent-operator-images/agent-dotnet-core@sha256:64f76993bf1bfb1aae2395438018df94c81ead4743fccaab890acc300d300e8c
dotnet-framework: ghcr.io/contrast-security-oss/agent-operator-images/agent-dotnet-framework@sha256:3f66d8272293c47b9e40d73047f2b1bee72cea792073d39944f0ca649f579ed8
java: ghcr.io/contrast-security-oss/agent-operator-images/agent-java@sha256:685f0dea5bb8d97049098598a22b8f4bd4f0dfd6fdce935030c512f71bef9722
nodejs: ghcr.io/contrast-security-oss/agent-operator-images/agent-nodejs@sha256:6fab2d62a950eea9a53995fa1692920a91d37b7f77f025090e4194dda72dcdf1
php: ghcr.io/contrast-security-oss/agent-operator-images/agent-php@sha256:500f422b330ec9940ce87a9c1b502079462d925d06f150e8cbc2db28e60c0116
python: ghcr.io/contrast-security-oss/agent-operator-images/agent-python@sha256:1748cf18d8d9166ce78593a69b783b9ebd67be759a2c07675a001727214b5233
flex: ghcr.io/contrast-security-oss/agent-operator-images/agent-flex@sha256:209bc66e9bf55beb262f742626a39c703afb18a441a31923b248d3a02afeb904