ci: bump install-with-cpm to @v2 so old Perls install deps

The Modernize CI commit (db41601) pinned perl-actions/install-with-cpm@v1
(an April 2024 tag). With its default version: main, that tag downloads
the latest cpm, which since cpm v0.999.0 requires Perl >= 5.24 (the "Lyon
Amendment"). So the Install Dependencies step failed before tests ran on
every Perl <= 5.22:

    Perl v5.24.0 required--this is only v5.22.4, stopped at cpm line 2.

Upstream already fixed this in install-with-cpm v2.4 (PR perl-actions/
install-with-cpm#96): when version resolves to main, no checksum is set,
and the perl is < 5.24, the action auto-substitutes cpm 0.998003 (the last
pre-Lyon release); modern Perls keep getting the latest cpm.

Bump all five Install Dependencies steps to @v2 to consume that fix. This
restores the 5.8-5.22 matrix without freezing modern Perls onto an old cpm.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: toddr

.github/workflows/testsuite.yml

@@ -23,7 +23,7 @@ jobs:
       - name: perl -V
         run: perl -V
       - name: Install Dependencies
-        uses: perl-actions/install-with-cpm@v1
+        uses: perl-actions/install-with-cpm@v2
         with:
           cpanfile: "cpanfile"
       - name: Makefile.PL
@@ -45,7 +45,7 @@ jobs:
       - name: perl -V
         run: perl -V
       - name: Install Dependencies
-        uses: perl-actions/install-with-cpm@v1
+        uses: perl-actions/install-with-cpm@v2
         with:
           cpanfile: "cpanfile"
       - name: Makefile.PL
@@ -90,7 +90,7 @@ jobs:
       - name: perl -V
         run: perl -V
       - name: Install Dependencies
-        uses: perl-actions/install-with-cpm@v1
+        uses: perl-actions/install-with-cpm@v2
         with:
           sudo: false
           cpanfile: "cpanfile"
@@ -115,7 +115,7 @@ jobs:
       - name: perl -V
         run: perl -V
       - name: Install Dependencies
-        uses: perl-actions/install-with-cpm@v1
+        uses: perl-actions/install-with-cpm@v2
         with:
           sudo: false
           cpanfile: "cpanfile"
@@ -141,7 +141,7 @@ jobs:
       - name: perl -V
         run: perl -V
       - name: Install Dependencies
-        uses: perl-actions/install-with-cpm@v1
+        uses: perl-actions/install-with-cpm@v2
         with:
           sudo: false
           cpanfile: "cpanfile"