shell-deps-check should have a way to ignore specific deps

For example, if a script has optional capabilities that require a desktop environment or an optional dependency, something like:

    # display, feh, gm, qdbus, qrencode are only necessary when displaying QR
    # codes or copying to a desktop environment's clipboard.
    - uses: test/tw/shell-deps-check
      with:
        files: /usr/bin/pass
        strict: false

could instead be:

    # display, feh, gm, qdbus, qrencode are only necessary when displaying QR
    # codes or copying to a desktop environment's clipboard.
    - uses: test/tw/shell-deps-check
      with:
        files: /usr/bin/pass
        ignore: display feh gm qdbus qrencode

and the output could be:

Dependency Check Results
========================
Analyzed: 1 shell script(s)
Checked against PATH: /usr/bin
Mode: report-only
/usr/bin/pass:
shell: /usr/bin/env bash
dependencies found: 27
 ✓ available (22): cat cp diff dirname find git grep head mkdir mktemp mv pkill rm rmdir sed sleep sort tail tr tree tty which
 - ignored (5): display feh gm qdbus qrencode
 ✗ missing (0):
---
Summary:
Total scripts analyzed: 1
Total dependencies found: 27
Total ignored commands: 5
Total missing commands: 0
Total GNU compatibility issues: 0
✗ Issues found in 0 of 1 file(s)

Start at the shell-deps-check action entry point and trace how its files and strict inputs are parsed and how dependency results are rendered. Add the ignore input and verify that ignored commands are separated from available and missing dependencies, with counts matching the example output. Validate the behavior using the sample /usr/bin/pass invocation.