fix: error when using default action config

[NyanKiyoshi]

This fixes a crash when using the default config from our repository, the workflow would error-out with the following:

$ docker-here \
    returntocorp/semgrep@sha256:396f4ad7a655289e764ab2f92733e6195c166ff2f042e0d40505a5850432b9ac \
    semgrep \
      --metrics=off \
      --config=./ ./

semgrep error: Invalid rule schema
  --> .github/dependabot.yaml:1
1  | version: 2
2  |
3  | updates:
4  |   - package-ecosystem: "github-actions"
5  |     directory: "/"
6  |     schedule:
7  |       interval: "monthly"
8  |     cooldown:
9  |       default-days: 21 # 3 weeks

One of these properties is missing: 'rules'

[ERROR] invalid configuration file found (1 configs were invalid)

This is due to Semgrep selecting all YAML files, including the ones under .github/. In the past, Semgrep was excluding hidden folders which isn't the case anymore.

Results after the changes:

$ docker-here \
    returntocorp/semgrep@sha256:396f4ad7a655289e764ab2f92733e6195c166ff2f042e0d40505a5850432b9ac \
    semgrep \
      --metrics=off \
      --config=./yaml \
      --config=./typescript ./

┌─────────────┐
│ Scan Status │
└─────────────┘
  Scanning 13 files (only git-tracked) with 2 Code rules:

  CODE RULES
  Scanning 6 files.

  SUPPLY CHAIN RULES

  No rules to run.

  PROGRESS

  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 100% 0:00:00

┌──────────────┐
│ Scan Summary │
└──────────────┘
Some files were skipped or only partially analyzed.
  Scan was limited to files tracked by git.
  Scan skipped: 2 files matching .semgrepignore patterns
  For a full list of skipped files, run semgrep with the --verbose flag.

Ran 1 rule on 6 files: 0 findings.