Bump combine_pdf from 1.0.23 to 1.0.26 in /back

Bumps [combine_pdf](https://github.com/boazsegev/combine_pdf) from 1.0.23 to 1.0.26.
- [Release notes](https://github.com/boazsegev/combine_pdf/releases)
- [Changelog](https://github.com/boazsegev/combine_pdf/blob/master/CHANGELOG.md)
- [Commits](boazsegev/combine_pdf@v1.0.23...v1.0.26)

---
updated-dependencies:
- dependency-name: combine_pdf
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

back/Gemfile.lock

@@ -531,7 +531,7 @@ GEM
     cloudfront-rails (0.4.0)
       railties (> 4.0)
     coderay (1.1.3)
-    combine_pdf (1.0.23)
+    combine_pdf (1.0.26)
       matrix
       ruby-rc4 (>= 0.1.5)
     concurrent-ruby (1.2.3)
@@ -793,7 +793,6 @@ GEM
       rake
     mini_magick (4.12.0)
     mini_mime (1.1.5)
-    mini_portile2 (2.8.5)
     minitest (5.22.2)
     mjml-rails (4.9.0)
     msgpack (1.6.0)
@@ -816,8 +815,13 @@ GEM
     nio4r (2.7.0)
     nlpcloud (1.0.43)
       rest-client (~> 2.1)
-    nokogiri (1.14.5)
-      mini_portile2 (~> 2.8.0)
+    nokogiri (1.14.5-aarch64-linux)
+      racc (~> 1.4)
+    nokogiri (1.14.5-arm64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.14.5-x86_64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.14.5-x86_64-linux)
       racc (~> 1.4)
     nori (2.6.0)
     oauth2 (1.4.9)