Relaxes DatasetReference.from_string and TableReference.from_string
validation.

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Fixes b/512823729 🦕

PR created by the Librarian CLI to initialize a release. Merging this PR
will auto trigger a release.

Librarian Version: v0.19.0
Language Image:
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<details><summary>google-cloud-bigquery: v3.42.0</summary>

##
[v3.42.0](google-cloud-bigquery-v3.41.0...google-cloud-bigquery-v3.42.0)
(2026-06-12)

### Features

* drop Python 3.7-3.9 support and regenerate (#17187)
([494abcd](494abcdf))

### Bug Fixes

* include pyopenssl as a dependency (#17345)
([1281790](12817900))

* bump requests from 2.21.0 to 2.33.0 in /packages/google-cloud-bigquery
(#17192)
([5283c92](5283c926))

* bump tqdm from 4.23.4 to 4.66.3 in /packages/google-cloud-bigquery
(#17194)
([8cda5fe](8cda5fe1))

* bump opentelemetry-instrumentation from 0.37b0 to 0.41b0 in
/packages/google-cloud-bigquery (#17195)
([f530a2c](f530a2c6))

* allow multi-part dataset IDs to support BigLake tables (#17137)
([f93911c](f93911c0))

### Documentation

* clarify Quickstart POST example (&lt;a
href=&#34;https://redirect.github.com/psf/requests/issues/6960&#34;&gt;#6960&lt;/a&gt;)&lt;/li&gt;
&lt;li&gt;Additional commits viewable in &lt;a
href=&#34;psf/requests@v2.21.0...v2.33.0&#34;&gt;compare
view&lt;/a&gt;&lt;/li&gt; &lt;/ul&gt; &lt;/details&gt; &lt;br /&gt;
([5283c92](5283c926))

* fix FAQ grammar in httplib2 example&lt;/li&gt; &lt;li&gt;&lt;a
href=&#34;psf/requests@774a0b837a194ee885d4fdd9ca947900cc3daf71&#34;&gt;&lt;code&gt;774a0b8&lt;/code&gt;&lt;/a&gt;
([5283c92](5283c926))

* same block as other sections&lt;/li&gt; &lt;li&gt;&lt;a
href=&#34;psf/requests@9c72a41bec8597f948c9d8caa5dc3f12273b3303&#34;&gt;&lt;code&gt;9c72a41&lt;/code&gt;&lt;/a&gt;
Bump github/codeql-action from 4.33.0 to 4.34.1&lt;/li&gt;
&lt;li&gt;&lt;a
href=&#34;psf/requests@ebf71906798ec82f34e07d3168f8b8aecaf8a3be&#34;&gt;&lt;code&gt;ebf7190&lt;/code&gt;&lt;/a&gt;
Bump github/codeql-action from 4.32.0 to 4.33.0&lt;/li&gt;
&lt;li&gt;&lt;a
href=&#34;psf/requests@0e4ae38f0c93d4f92a96c774bd52c069d12a4798&#34;&gt;&lt;code&gt;0e4ae38&lt;/code&gt;&lt;/a&gt;
([5283c92](5283c926))

* exclude Response.is_permanent_redirect from API docs (&lt;a
href=&#34;https://redirect.github.com/psf/requests/issues/7244&#34;&gt;#7244&lt;/a&gt;)&lt;/li&gt;
&lt;li&gt;&lt;a
href=&#34;psf/requests@d568f47278492e630cc990a259047c67991d007a&#34;&gt;&lt;code&gt;d568f47&lt;/code&gt;&lt;/a&gt;
([5283c92](5283c926))

</details>