Validate download checksums if possible

[viceice]

Tools

• [x] composer (sha256) #886
• [x] dart #772
• [ ] docker (no checksums)
• [ ] #2058
• [x] erlang #870
• [x] flutter #806
• [x] flux (sha256?) #1204
• [ ] #2506
• [x] #2062
• [x] gradle (sha256, https://services.gradle.org/distributions)
• [x] #2063
• [x] #2064
• [x] java (sha256, sha512)
• [ ] jb jsonnet-bundler/jsonnet-bundler#172
• [x] #2065
• [x] maven #733
• [x] #2066
• [x] node #725
• [x] php #873
• [ ] #2067
• [x] python #874
• [x] #2966
• [x] #2068
• [ ] sbt (sha256)
• [ ] scala (sha256, v3+ at https://github.com/scala/scala3/releases)
• [ ] switft (gpg)
• [ ] #3032
• [ ] #3033

Notes

Some tools are missing here, they get installed via their package manager, so not yet possible to validate checksums.