CI: fix release pr target (#90999)

* use inputs.target as checkout ref, and `main` for all reused actions.

pkg/build/actions/bump-version/action.yml

@@ -7,21 +7,6 @@ inputs:
 runs:
   using: "composite"
   steps:
-    - uses: actions-ecosystem/action-regex-match@v2.0.2
-      if: ${{ github.event.inputs.version != '' }}
-      id: regex-match
-      with:
-        text: ${{ github.event.inputs.version }}
-        # https://semver.org/
-        regex: '^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$'
-    - name: Validate input version
-      if: ${{ steps.regex-match.outputs.match == '' && github.event.inputs.version != '' }}
-      shell: bash
-      run: |
-        echo "The input version format is not correct, please respect:\
-        major.minor.patch, major.minor.patch-preview or major.minor.patch-preview<number> format. \
-        example: 7.4.3, 7.4.3-preview or 7.4.3-preview1"
-        exit 1
     - uses: actions/setup-go@v4
       with:
         go-version-file: go.mod